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Avocats, autres représentants, expert(s), secrétaire du tribunal

Final Award

GLOSSARY OF NAMES

This Glossary contains key terms used in the Award. Some place names, geographic features, and locations have varied spellings; these are also identified below.

1898 Gleichen Handbook "Handbook of the Sudan" compiled in the Intelligence Division, War Office by Captain Count Gleichen (1898)
1905 Gleichen Handbook "The Anglo-Egyptian Sudan: A Compendium Prepared by Officers of the Sudan Government" edited by Lieutenant-Colonel Gleichen (1905)
ABC Abyei Boundaries Commission
ABC Experts or Experts The five experts nominated by the United Kingdom, the United States of America and the IGAD to the ABC (Ambassador Donald Patterson, Dr. Kassahun Berhanu, Prof. Shadrack B.O. Gutto, Dr. Douglas H. Johnson, Prof. Godfrey Muriuki)
ABC Experts' Report or Report Report presented by the ABC Experts to the Sudanese Presidency on July 14, 2005
Abyei Appendix or Abyei Annex Appendix to the Abyei Protocol relating to the Parties' "Understanding on Abyei Boundaries Commission"
Abyei Area or Formula the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905
Abyei Protocol Protocol on "The Resolution of Abyei Conflict" signed by the Parties on May 26, 2004
Abyei Referendum A referendum to be held among the residents of Abyei (simultaneously with the referendum of Southern Sudan) allowing them to vote on whether Abyei shall retain its special administrative status in the north or become part of Bahr el Ghazal
Abyei Road Map "Road Map for the Return of IDPs and Implementation of Abyei Protocol" signed by the Parties on June 8, 2008
Abyei Town Town of Abyei located north of the Bahr el Arab river
Anglo-Egyptian Condominium (or Joint British and Egyptian government of
Condominium) Sudan (1899-1956)
Arbitration Agreement Arbitration Agreement between the GoS and the SPLM/A on delimiting the Abyei Area signed on July 7, 2008
Babanusa Sandy area in southern Kordofan, north of Muglad
Baggara Arab nomadic tribes ofWestern Sudan (southern Kordofan and Darfur) and Eastern Chad

Bahr el Arab Also referred to as Kir in Dinka, Bahr ed Deynka, Bahr el Homr, Bahr el Jange, Chonyan or Gurf; river that runs from Southern Darfur through Southern Kordofan, and flows into the Bahr el-Ghazal river in the Upper Nile Province
Bahr el Ghazal Also known as Bahr el Gazal or Nam; river that runs through the Upper Nile Province; Province of Sudan bordering the southwest corner of Kordofan
Bahr el Ghazal Annual Reports Any of the "Reports on the Finances, Administration, and Condition of the Sudan, Annual Report Bahr El Ghazal Province," including those published from 1902 to 1905
Bahr el Homr A reference to either the Bahr el Arab or the Ragaba ez Zarga in the early 20th century
Bayldon, Sub-Lieutenant R.N. Military officer who explored a portion of the Bahr el Arab in early 1905
Boulnois, W.A. Governor of Bahr el Ghazal Province (19041905)
CivSec or Civsec A reference to the Sudan Civil Secretary's files in Khartoum during the period of the Anglo-Egyptian Condominium
Community Mapping Project Community mapping project conducted in a portion of the Abyei region with the involvement of a professional community mapping expert, Dr. Peter Toole, and members of the Ngok Dinka community
CPA Comprehensive Peace Agreement signed by the Parties on January 9, 2005
Cunnison, Professor Ian Professor of social anthropology who lived with and wrote about the Baggara Humr in the 1950s
Dar Arabic word for homeland or tribal region
Darfur Province of Sudan bordering the west of Kordofan
Dinka Also known as Jange; a collection of tribes of Nilotic origin including, inter alia, the Ngok, the Rueng and the Twic
Dupuis, Inspector C.J. District Commissioner of West Kordofan in 1921
GoS Government of Sudan
Goz Sandy area of transit south of Muglad
Henderson., K.K.D. (1903-1988) Governor of Darfur Province from 1949-1953
Howell, P.P. Anthropologist and District Commissioner at Nahud (Kordofan) in 1948
Humr Also known as Homr; cattle-owning nomadic Arab tribe of southern Kordofan, subgroup of the Messiriya

Humr omodiya Administrative term referring to a sub-group of Humr under a tribal headman (omda)
Inter-Governmental Authority on Regional African organization comprised by
Development or IGAD the seven countries in the Horn of Africa (Djibouti, Ethiopia, Kenya, Somalia, Sudan, Uganda, and Eritrea)
Interim National Constitution Interim National Constitution of the Republic of Sudan adopted on July 6, 2005
Khartoum Capital of Sudan, located in the north of Sudan
Kordofan Also referred to as Kurdufan; Western Province of Sudan bordering Darfur in the west, Bahr el Ghazal in the southwest and Upper Nile in the southeast
Kordofan Annual Reports Any of the "Reports on the Finances, Administration, and Condition of the Sudan, Annual Report Kordofan Province," including those published from 1902 to 1905
Lloyd, Captain H.D.W. (1872-1915) Governor of Kordofan Province (1908)
Mahdiyya Time of Mahdist rule of the Sudan (18851898)
Mahon, B.T. (1862-1930) Governor of Kordofan Province (1901-1906)
March 1905 SIR The Sudan Intelligence Report, No. 128 (March 1905)
Mardon, H.W. author and cartographer who wrote "A Geography of Egypt and the Anglo-Egyptian Sudan" (1906)
MENAS Expert Report "The Boundaries and Hydrology of the Abyei Area, Sudan" by Menas Borders Ltd. (February 2009; expert report commissioned by the SPLM/A for this arbitration)
Misseriya also known as Messeria or Messiria; nomadic tribe of Baggara Arabs
Muglad Home and cultivation area of the Humr, south of the Babanusa and north of the goz
Nine Ngok Dinka Chiefdoms Abyior, Achaak, Achueng, Alei, Anyiel, Bongo, Diil, Manyuar, Mareng
Nuers a nilotic tribe
O'Connell, J.R. Governor of Kordofan in 1906
Parties GoS and the SPLMA, collectively
PCA Permanent Court of Arbitration
PCA Financial Assistance Fund a fund established by PCA Member States that helps developing countries meet part of the costs involved in international arbitration or other means of dispute settlement offered by the PCA.
Percival, Captain C. British officer who traveled to the Abyei region in 1904 and 1905
Ragaba also spelled regaba or regeba; seasonal watercourse

Ragaba ez Zarga also known as Ragaba ez-Zarga, Ngol, Ragaba Zarga; also referred to, in the early 20th century, as Bahr el Arab due to geographic confusion; watercourse located north of the Bahr el Arab and the Ragaba Umm Biero
Ragaba Umm Biero also known as Nyamora, Yamoi, Umm Rebeiro, Umm Bieiro, Umbieiro, Umm Bioro; watercourse located north of, and flowing into, the Bahr el Arab
Rizeigat Also referred to as Rezeigat; Baggara tribe located mostly in the Province of Darfur
Robertson, J.W. (1899-1983) District Commissioner of Western Kordofan (1933-1936); Civil Secretary (1945-1953)
Rules of Procedure Rules of procedure prepared by the ABC Experts pursuant to Section 4 of the Abyei Appendix and agreed to by the Parties on April 11, 2005
Sheikh Rihan Gorkwei also known as Sultan Rihan; chief of the Twic Dinka in 1905
SPLM/A Sudan People's Liberation Movement/Army
Sultan Rob Paramount Chief Arop Biong; chief of the Ngok Dinka of southwest Kordofan in 1905
Terms of Reference Terms of reference adopted by the Parties on March 12, 2005
Territorial Interpretation the GoS interpretation of the Formula (see paras. 232 et seq.)
Tibbs, Michael Assistant District Commissioner of the Western Kordofan District (1952-1953); District Commissioner of the Dar Messeria District (1953-1954)
Tribal Interpretation the SPLM/A interpretation of the Formula (see paras. 232 et seq.)
Turkiyya period of Turkish-Egyptian rule of Sudan (1821-1881)
Upper Nile Province of Sudan bordering Kordofan in the east and the southeast
Wilkinson, Major E.B.(1864-1946) Governor of Gezira Province (1903); Governor of Kassala Province (1903-1908); Governor of Berber Province (1908-1910)
Wingate, Sir. R. (1861-1953) Governor-General of Sudan (1899-1916)
Wingate's 1904 Memorandum Report entitled "Reports on the Finances, Administration, and Condition of the Sudan, Memorandum by Major General Sir R. Wingate" published in 1904
Wingate's 1905 Memorandum Report entitled "Reports on the Finances, Administration, and Condition of the Sudan, Memorandum by Major General Sir R. Wingate" published in 1905

CHAPTER I - PROCEDURAL HISTORY

A. THE ARBITRATION AGREEMENT

1.
On July 7, 2008, the Government of Sudan ("GoS") and the Sudan People's Liberation Movement/Army ("SPLM/A," and together with the GoS, the "Parties") signed the "Arbitration Agreement between The Government of Sudan and The Sudan People's Liberation Movement/Army on Delimiting Abyei Area" ("Arbitration Agreement").
2.
As stated in the Arbitration Agreement, a dispute has arisen between the Parties regarding whether or not the experts ("ABC Experts" or "Experts") of the Abyei Boundaries Commission ("ABC"), established pursuant to the Comprehensive Peace Agreement signed by the Parties on January 9, 2005 ("CPA"), exceeded their mandate as per the provisions of the CPA, the Protocol signed by the Parties on May 26, 2004 on the Resolution of Abyei Conflict ("Abyei Protocol"), the appendix to the Abyei Protocol ("Abyei Appendix" or "Abyei Annex")1, and the ABC's terms of reference ("Terms of Reference") and rules of procedure ("Rules of Procedure").
3.
Under Article 1.1 of the Arbitration Agreement, the Parties agreed to refer their dispute to final and binding arbitration under the Arbitration Agreement and the PCA Optional Rules for Arbitrating Disputes between Two Parties of Which Only One is a State ("PCA Rules"), subject to such modifications as the Parties agreed in the Arbitration Agreement or may agree in writing. Under Article 1.2, the Parties agreed to form an arbitration tribunal ("Tribunal") to arbitrate their dispute.
4.
In accordance with Article 12.1 of the Arbitration Agreement, on July 11, 2008, the Parties deposited the Arbitration Agreement with the Secretary-General of the Permanent Court of Arbitration ("PCA").
5.
Under Article 1.3 of the Arbitration Agreement, the Parties agreed that the International Bureau of the PCA is to act as registry and provide administrative support in accordance with the Arbitration Agreement and the PCA Rules. Pursuant to Article 1.4, the Parties designated the Secretary-General of the PCA as the appointing authority for the proceedings.
6.
Under Article 2 of the Arbitration Agreement, the issues to be determined by the Tribunal are the following:

(a) Whether or not the ABC Experts had, on the basis of the agreement of the Parties as per the CPA, exceeded their mandate which is 'to define (i.e. delimit) and demarcate the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905' as stated in the Abyei Protocol, and reiterated in the Abyei Appendix and the ABC Terms of Reference and Rules of Procedure.

(b) If the Tribunal determines, pursuant to Sub-article (a) herein, that the ABC Experts did not exceed their mandate, it shall make a declaration to that effect and issue an award for the full and immediate implementation of the ABC Report.

(c) If the Tribunal determines, pursuant to Sub-article (a) herein, that the ABC Experts exceeded their mandate, it shall make a declaration to that effect, and shall proceed to define (i.e. delimit) on map the boundaries of the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905, based on the submissions of the Parties.

B. CONSTITUTION OF THE ARBITRAL TRIBUNAL

7.
Under Article 5 of the Arbitration Agreement, the Parties agreed that the Tribunal shall be composed of five arbitrators, that each Party shall appoint two arbitrators, and that the four Party-appointed arbitrators shall appoint the fifth arbitrator. The Parties agreed not to designate persons other than current or former members of the PCA or members of tribunals for which the PCA acted as registry. Party-appointed arbitrators were to be independent, impartial, highly qualified, and experienced in similar disputes.
8.
On July 16, 2008, in accordance with Article 5.3 of the Arbitration Agreement, the Secretary-General of the PCA provided the Parties with a full list of current or former members of the PCA or members of tribunals for which the PCA acted as registry ("PCA Arbitrators List").
9.
On August 14, 2008, in accordance with Articles 5.2 and 5.4 of the Arbitration Agreement, the GoS appointed as arbitrators His Excellency Judge Awn Al-Khasawneh and Professor Dr. Gerhard Hafner.
10.
On August 15, 2008, in accordance with Articles 5.2 and 5.4 of the Arbitration Agreement, the SPLM/A appointed as arbitrators Professor W. Michael Reisman and Judge Stephen M. Schwebel.
11.
Before August 22, 2008, in accordance with Article 5.6 of the Arbitration Agreement, each of the four Party-appointed arbitrators signed declarations of independence, impartiality, and commitment, and such declarations were immediately communicated by the PCA to the Parties.
12.
On September 6, 2008, in accordance with Article 5.7 of the Arbitration Agreement, the four Party-appointed arbitrators met in The Hague, The Netherlands to consider candidates for the fifth arbitrator. Article 5.8 of the Arbitration Agreement provides that the fifth arbitrator might be selected from or outside the PCA Arbitrators List, and shall be a "renowned lawyer of high professional qualifications, personal integrity, and moral reputation" with experience in similar disputes.
13.
On September 24, 2008, in accordance with Article 5.9 of the Arbitration Agreement, the four Party-appointed arbitrators communicated to the Parties, through the Secretary-General of the PCA, an identical list of five candidates for the fifth arbitrator, attaching full curricula vitae of the candidates.
14.
On October 12, 2008, in accordance with Article 5.10 of the Arbitration Agreement, the Parties returned the candidates list after having deleted the name or names to which they objected and numbered the remaining candidates in order of preference. All the candidates on the list were objected to by either Party or by both Parties. Article 5.12 was then triggered, requiring the Secretary-General of the PCA to appoint, in consultation with the four arbitrators, within fifteen days of receiving the objections, the fifth arbitrator from outside the candidates' list, having due regard to Article 5.8 of the Arbitration Agreement.
15.
The Secretary-General of the PCA consulted with the four Party-appointed arbitrators in accordance with Articles 5.8 and 5.12 of the Arbitration Agreement and, on October 27, 2008, the Secretary-General appointed Professor Pierre-Marie Dupuy as the fifth and presiding arbitrator ("Presiding Arbitrator").
16.
On October 30, 2008, in accordance with Article 5.13 of the Arbitration Agreement, the Presiding Arbitrator signed a declaration of independence, impartiality, and commitment which was then immediately communicated by the PCA to the Parties.

C. COMMENCEMENT AND TIMING OF ARBITRATION PROCEEDINGS

17.
Pursuant to Article 4.1 of the Arbitration Agreement, the arbitration process was deemed to have commenced on June 8, 2008.
18.
Article 4.2 of the Arbitration Agreement provides that the arbitration proceedings "shall commence on the date of the formation of the Tribunal which shall start its work as soon as it is constituted." For purposes of Article 4.2, the date of the formation of the Tribunal was October 30, 2008, the date on which the declaration of the fifth and presiding arbitrator was signed and communicated to the Parties.
19.
According to Article 4.3 of the Arbitration Agreement, the Tribunal "shall endeavor to complete the arbitration proceedings including the issuance of the final award within a period of six months from the date of the commencement of arbitration proceedings subject to three months extension." Article 9.1 refers specifically to the award, stating: "Subject to Article 8(7)... the final award shall be rendered by the Tribunal within a maximum of ninety days from the closure of submissions."
20.
Article 8.7 of the Arbitration Agreement provides that notwithstanding Article 4.3, the Tribunal shall be empowered to extend for good cause the periods established for the arbitration proceedings on its own motion or at the request of either Party. The total cumulative extension of the periods granted by the Tribunal at the request of either Party could not exceed thirty days for each Party.

D. PRELIMINARY PROCEDURAL MEETING

21.
On November 24, 2008, the Tribunal held a preliminary procedural meeting with the Parties at the Peace Palace in The Hague.
22.
Present at the Preliminary Procedural Meeting were:

Tribunal: Professor Pierre-Marie Dupuy

Judge Awn Al-Khasawneh

Professor Dr. Gerhard Hafner

Judge Stephen M. Schwebel

Professor W. Michael Reisman

For the GoS: Professor James Crawford SC

For the SPLM: Mr. Gary Born

Ms. Wendy Miles

Professor Paul R. Williams

Ms. Vanessa Jiménez

Dr. Luka Biong Deng

Hon. Deng Arop Kuol

Mr. Kuol Dueim Kuol

Mr. Mathew Otoromoi Martinson

Registry: Ms. Judith Levine

Mr. Aloysius Llamzon

23.
The Parties and Members of the Tribunal signed the Terms of Appointment at the Procedural Meeting.
24.
Pursuant to the Terms of Appointment, the Parties confirmed, among other things, that the members of the Tribunal had been validly appointed in accordance with the Arbitration Agreement and the PCA Rules, and that the Parties had no objection to the appointment of each member of the Tribunal on the grounds of conflict of interest or lack of independence or impartiality.
25.
The Parties further confirmed that the PCA would serve as Registry and that the Tribunal may appoint a member of the PCA International Bureau to act as Registrar for the proceedings, and for this purpose the Tribunal appointed Ms. Judith Levine, PCA Legal Counsel, as Registrar. From March 13, 2009, Mr. Aloysius Llamzon, PCA Legal Counsel, was designated as Acting Registrar.
26.
At the Preliminary Procedural Meeting, the Tribunal (in consultation with the Parties) set a schedule for the written and oral phases of the proceedings consistent with the timelines set by Article 8 of the Arbitration Agreement. At the request of the GoS, an extension of 14 days for the submission of Counter-Memorials was granted pursuant to Article 8.7 of the Arbitration Agreement.
27.
In accordance with Article 8.6 of the Arbitration Agreement, shortly after the Preliminary Procedural Meeting, copies of the Terms of Appointment, Transcript of Proceedings, and the schedule for the written and oral phases of the proceedings were published on the PCA's website (www.pca-cpa.org).

E. DEPOSITS AND THE PCA FINANCIAL ASSISTANCE FUND

28.
Article 11 of the Arbitration Agreement provides:

1. The Presidency of the Republic of Sudan shall direct for the payment of the cost of the arbitration from the Unity Fund regardless of the outcome of the arbitration.

2. The Government of the Sudan shall apply to the PCA Financial Assistance Fund and the Parties may solicit additional assistance from the international community.

29.
On July 11, 2008, the Presidency of the Republic of Sudan submitted a request to the PCA Secretary-General for financial assistance from the PCA Financial Assistance Fund.
30.
A preliminary deposit of EUR 40,000 was requested from the Parties on August 28, 2008 for purposes of covering the expenses associated with the meeting in The Hague pursuant to Article 5.7 of the Arbitration Agreement. The Presidency of the Republic of Sudan duly paid this amount on September 6, 2008.
31.
On November 24, 2008, in accordance with Article 41 of the PCA Rules and pursuant to paragraph 7.1 of the Terms of Appointment, the Tribunal requested that the Presidency of the Republic of Sudan establish an initial deposit of EUR 1,000,000.00 (equivalent to EUR 500,000 for each Party) as an advance on costs of the arbitration.
32.
Shortly thereafter, on December 4, 2008, the PCA transmitted the request for financial assistance from the Presidency of the Republic of Sudan to the Board of Trustees of the PCA Financial Assistance Fund. On December 18, 2008, the Board of Trustees approved an allocation of EUR 400,000 to be made from the PCA Financial Assistance Fund towards the deposit in this case. The remaining portion of the initial deposit, EUR 600,000, was received by the PCA from the Presidency of the Republic of Sudan on January 15, 2009.
33.
In accordance with Article 41(2) of the PCA Rules and Paragraph 7.3 of the Terms of Appointment, the Tribunal requested a supplementary deposit of EUR 750,000 on March 10, 2009. By letter dated April 13, 2009 addressed to the PCA, the GoS confirmed that the requested supplementary deposit had been transferred to the PCA to meet the expenses of the Tribunal. The PCA acknowledged receipt of EUR 750,000 on April 17, 2009.
34.
On May 8, 2009, the Tribunal, in further reliance on Article 41(2) of the PCA Rules and Paragraph 7.3 of the Terms of Appointment, and in view of the work already completed and currently anticipated in relation to the proceedings, requested a supplementary deposit of EUR 500,000. By letter dated June 3, 2009 addressed to the PCA, the GoS confirmed that the requested supplementary deposit was transferred by wire on that date. The PCA acknowledged receipt of EUR 500,000 on June 9, 2009.
35.
As of the date of this Award, Norway, The Netherlands, and France have made Financial Assistance Fund contributions towards the financing of part of the costs of these proceedings.

F. WRITTEN PLEADINGS PHASE OF THE PROCEEDINGS

36.
In accordance with Article 8.3(i) of the Arbitration Agreement and the schedule set by the Tribunal, the Parties filed written Memorials on December 18, 2008, accompanied by witness statements, expert reports, maps, documentary evidence and legal authorities.
37.
The GoS made the following formal submissions in its Memorial:

For the reasons set out in this Memorial, the Government of Sudan respectfully requests the Tribunal to adjudge and declare:

(a) pursuant to Article 2(a) of the Arbitration Agreement, that the ABC Experts exceeded their mandate as stated in the Abyei Protocol, and reiterated in the Abyei Appendix and the ABC Terms of Reference and Rules of Procedure;

(b) pursuant to Article 2(c) of the Arbitration Agreement, that the boundaries of the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905 are as shown on Figure 17 (page 159), being the area bounded on the north by the Bahr el-Arab and otherwise by the boundaries of Kordofan as at independence.

38.
The map referenced in paragraph (b) of the GoS Submission is:
39.
The SPLM/A made the following formal submissions in its Memorial:

For the reasons set forth in this Memorial, the SPLM/A respectfully requests that the Arbitral Tribunal make an Award granting the following relief:

(a) A declaration that the ABC Experts did not, on the basis of the agreement of the Parties as per the CPA, exceed their mandate which is "to define (i.e. delimit) and demarcate the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905" as stated in the Abyei Protocol, and reiterated in the Abyei Annex and the ABC Terms of Reference and Rules of Procedure;"

(b) On the basis of relief in the terms of sub-paragraph (a) above, a declaration that the boundaries of the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905 are as defined and delimited by the ABC Experts in the ABC Report, and that definition and delimitation, and the ABC Report shall be fully and immediately implemented by the Parties;

(c) In the alternative, if the Tribunal determines that the ABC Experts exceeded their mandate and makes a declaration to that effect, a declaration that the boundaries of the area of the nine Ngok Dinka Chiefdoms transferred to Kordofan in 1905 are the current boundary of Kordofan and Bahr el-Ghazal to the south extending to 10°35'N latitude to the north and the current boundary of Kordofan and Darfur to the west extending to 32°15'E longitude to the east;

(d) A declaration that the Tribunal's Award is final and binding on the Parties;

(e) Costs, including the direct costs of the arbitration, as well as fees and other expenses incurred in participating in the arbitration, including but not limited to, the fees and/or expenses incurred in relation to the Tribunal, solicitors and counsel, and any ABC Experts, consultants and witnesses, internal legal costs, the costs of translations, archival research and travel; and

(f) Such additional or other relief as may be just.

40.
In accordance with Article 8.3(ii) of the Arbitration Agreement and the schedule set by the Tribunal, the Parties filed their respective Counter-Memorials on February 13, 2009, accompanied by witness statements, expert reports, maps, documentary evidence and legal authorities.
41.
In its Counter-Memorial, the GoS, for the reasons set out in its Counter-Memorial, "and rejecting the arguments contained in the Memorial of the SPLM/A […] reaffirm[ed] the Submissions appearing in its Memorial." Similarly, the SPLM/A reaffirmed the formal submissions and request for relief made in its Memorial.2
42.
In accordance with Article 8.3(iii) of the Arbitration Agreement and the schedule set by the Tribunal, the Parties filed their respective Rejoinders on February 28, 2009.
43.
The GoS, for the reasons set out in its Rejoinder, "and rejecting the arguments contained in the Memorial and Counter-Memorial of the SPLM/A […] reaffirm[ed] its previous Submissions." On its part, the SPLM/A similarly reaffirmed the formal submissions and request for relief made by it in its Memorial.3
44.
In accordance with Article 8.6 of the Arbitration Agreement, copies of the Parties' pleadings were published on the PCA's website (www.pca-cpa.org).
45.
Summaries of the Parties' written pleadings are found infra in Chapter III.

G. TRIBUNAL'S REQUEST FOR CERTAIN DOCUMENTS; ACCESS TO THE ARCHIVES OF SUDAN

46.
On March 17, 2009, the following communication from the Tribunal was conveyed by the PCA to the Parties:

The Tribunal notes the statements made by the Sudan People's Liberation Movement/Army ("SPLM/A") in its Rejoinder of February 28, 2009 ("Rejoinder") that the Government of Sudan ("Government") has had full access to archives containing the sketch maps and cartographic records prepared by or for Messrs. Wilkinson, Percival, Hallam, and Whittingham, while the SPLM/A has not, in its view, been fully provided with or given access to these documents. (see, for example, paragraphs 432(g), 458, 460, 485, 564, 569, 571-72, and 574-76 of the Rejoinder).

The Tribunal appreciates that the Government has disclosed portions of the aforementioned maps in its written pleadings. The Tribunal also acknowledges that the Parties were entitled to submit extracts of documents in the exhibits to their written pleadings (see Transcript of the Nov. 24, 2008 Procedural Hearing, pp. 34-35).

However, in light of the potential importance of these contemporaneous documents, and recalling the need for a final and peaceful settlement of this dispute and the principle of equality that the Tribunal has a duty to accord to the Parties (as reflected in Article 15(1) of the PCA Rules):

1. The Tribunal requests, pursuant to Article 24(3) of the PCA Rules, that the Government of Sudan provide the Tribunal and the SPLM/A, by March 30, 2009, with copies of the full sketch maps/records prepared by or for Messrs. Wilkinson, Percival, Whittingham, and Hallam that are within the Government's possession or control, including specifically the full sketch maps and cartographic records relating to the following maps found in Volume III of the Government's CounterMemorial:

a. Map 13b (Wilkinson's Sketch Map);

b. Map 14a (Percival 1904 Route Map - Lake Leilak to Wau)

c. Map 14b (Percival's Sketch Map - River Kir to Wau);

d. Map 16b (Hallam's Sketch Map); and

e. Map 18b (Wittingham's Sketch Map).

2. The Tribunal is prepared to hear from both Parties as to the necessity of granting the SPLM/A full access to relevant archival documents within the Government's control (including access to the Sudan Survey Department), through the following process:

a. the SPLM/A may, by March 27, 2009, send a written request ("Request") to the Government, with a copy to the Tribunal, containing a reasonably specific description of documents, maps and/or cartographic records sought.

b. The Government may either: (i) facilitate full and timely access to the archival documents sought in the Request, or (ii) file before the Tribunal, with a copy to the SPLM/A, by April 6, 2009, a written objection to the Request ("Objection"), containing its specific grounds for objection.

c. The Tribunal will then consider the Request and Objection, and may issue the appropriate order.

47.
By letter to the PCA on the same date, the SPLM/A stated that it had previously made requests for access to both the Sudan Survey Department ("Survey Department") and the Sudan National Records Office ("NRO") and was granted access to the NRO on March 2, 2009. The SPLM/A reiterated its request for "full and unhindered access to the SPLM/A and [its] counsel to the relevant archival documents at the Survey Department, including those specified in the [correspondence enclosed with this letter] to the Survey Department and the NRO."
48.
On March 19, 2009, Mr. Bakri Hasan Salih, the Minister of the Presidency of the Republic of Sudan, by letter addressed to the PCA, explained that the Presidency and the Government of National Unity of the Republic of Sudan are composed of both the National Congress Party and the SPLM/A as main partner-parties, and both are responsible for all Government Departments in the Sudan, including the NRO and the Survey Department. He further explained that "the archives in Sudan, be they in the NRO, the Survey Department or any other Department, are open to the public. There is no requirement of obtaining prior access to any of them." He rejected the allegation that the SPLM/A was denied access to the NRO and the Survey Department and maintained that the SPLM/A's counsel were welcome to visit the NRO, the Survey Department and any other archive unit in the country.
49.
By letter dated March 19, 2009 addressed to the PCA, the SPLM/A explained that although the NRO itself may be open to the public (subject to first obtaining necessary permits and passes), access to the documents within those archives is not straightforward. The SPLM/A remained deeply concerned that its representatives would not be granted full or proper access to the materials it required. It also requested "written confirmation from the [GoS] that [it] will make the necessary arrangements to ensure the security of [the SPLM/A's] legal team [during] their visit to Khartoum." The SPLM/A further requested the GoS to provide complete copies of: (1) the 1903 Wilkinson sketch map; (2) the 1904 Percival sketch map segment from the Bahr el Arab/Kir to Keilak; (3) the 1905 Percival sketch map segment from "Golo" to Taufikia; (4) the 1910 Whittingham sketch maps and route notes; and (5) the 1907 Hallam sketch map and route notes.
50.
In reply to the Tribunal's communication dated March 17, 2009, the GoS, by letter dated March 19, 2009, stated that "the [GoS] has always sought to cooperate with the SPLM/A fully in the conduct of this arbitration. This is evidenced by the fact that it provided a number of documents promptly in spite of the additional burden this represented at the time of finalization of the Rejoinder. If some documents and maps were not supplied following the SPLM/A's requests, this was simply because they had not been found." The GoS noted that when the SPLM/A formally applied for access to the Survey Department and the NRO by two letters dated February 19, 2009, it was already after the February 13, 2009 exchange of Counter-Memorials and nine days before the filing of the Rejoinders. According to the GoS, "it was no longer appropriate at [that] point for any of the Parties to file any new documents without the specific leave of [this] Tribunal." The GoS also alleged that representatives of the SPLM/A were expected to visit the NRO on February 28, 2009 but failed to appear, and that "it is significant that the date coincides with the filing date of the Rejoinder, in which the SPLM/A complained of not having had access to the Sudan Archives, while it had only sought access on February 19, 2009 and had not thereafter followed up on its request."
51.
Noting that the GoS would be providing access to the Survey Department archives, the SPLM/A stated through its letter dated March 20, 2009 that it did not consider it necessary for the Tribunal to hear the Parties any further on point two of the Tribunal's communication dated March 17, 2009, but requested the opportunity to make further submissions on the issue following its inspection of the NRO and Survey Department archives. The SPLM/A also expressed surprise that the GoS had been unable to locate complete copies of certain records and thus reiterated its request for an order from the Tribunal instructing the GoS to produce the full and complete sketch maps, cartographic records and route reports relating to the requested maps and records, or to procure that the Sudan Survey Department produce them. Further, it sought an order from the Tribunal instructing the GoS to provide complete copies of the full sketch maps, cartographic records and route reports prepared by or for Mr. Percival in relation to his 1905 trek from River Pongo to Taufilia, or to arrange for the Sudan Survey Department to produce them.
52.
On March 23, 2009, the GoS accused the SPLM/A of "attempt[ing] to seek leave to embark on an unfettered fishing expedition" and noted that "SPLM/A's own failure to exercise due diligence is no justification for a late request to seek access to such a potentially wide array of documents."
53.
On March 24, 2009, the Tribunal sent the following communication to the Parties through the PCA:

The Tribunal thanks the Parties for the following letters in response to its communication of March 17, 2009 ("Communication"):

From the Government of Sudan ("GoS")

1. Letter dated March 19, 2009 from the Minister of the Presidency of the GoS

2. Letter dated March 19, 2009 from the Agent of the GoS

3. Letter dated March 23, 2009 from the Agent of the GoS

From the Sudan People's Liberation Movement/Army ("SPLM/A")

1. Letter dated March 17, 2009

2. Letter dated March 19, 2009

3. Letter dated March 20, 2009

The Tribunal expresses its appreciation at the GoS' assurances that the SPLM/A continues to enjoy full access to the Archives of Sudan (last paragraph, p. 3, letter of the Agent of the GoS dated March 19, 2009; first paragraph, p. 5, letter of the Agent of the GoS dated March 23, 2009). The Tribunal also takes note of the SPLM/A's statement that, "[a]t the present, the SPLM/A does not consider it necessary for the Tribunal to hear the Parties any further on point two of the PCA's letter dated 17 March 2009." (third paragraph, p.1, letter of the SPLM/A dated March 20, 2009). In view of the positions expressed by the Parties, the Tribunal shall take no further action at this time in relation to Point 2 of its Communication.

On Point 1 of its Communication, where the Tribunal requested that the GoS provide it and the SPLM/A with copies of the full sketch maps/records listed therein, the Tribunal notes that "the Government of Sudan will respond further by 30 March 2009." (last paragraph, p.4, letter of the Agent of the GoS dated March 23, 2009) The Tribunal requests that the additional documents sought by the SPLM/A in the penultimate paragraph of its March 20, 2009 letter (i.e., the "full sketch map(s), cartographic records and route reports prepared by or for Mr. Percival in relation to his 1905 trek from River Pongo to Taufikia.") be considered a further document to be provided by March 30, 2009 under Point 1 of the Tribunal's Communication.

The Tribunal looks forward to the GoS' response to Point 1, and expects that the GoS will provide these maps/records or, if necessary, provide satisfactory reasons for the unavailability of those documents not produced. The Tribunal is thankful for the spirit of cooperation the GoS has demonstrated in this matter.

54.
On March 26, 2009, the SPLM/A sent a letter to the GoS (with copies to the Tribunal and the PCA) noting that "the statements in your letters regarding the past accessibility of the NRO and Sudan Survey Department archives are inaccurate. In fact, both the SPLM/A and its expert have prior experience in the NRO of being denied access to documents. […] As for the Sudan Survey Department archive, as soon as the SPLM/A legal representatives became aware that there existed a separate archive of documents outside of the NRO that contained additional (and previously unseen) historic records directly relevant to the issues in dispute in this arbitration, to which the [GoS's] expert has been granted apparent unfettered access, the SPLM/A directly requested the same. The SPLM/A's requests in February 2009 were simply ignored." The SPLM/A also alleged that its legal representatives sent to the Survey Department in Khartoum have been "wholly obstructed from viewing a single relevant document" and have been "prohibited from carrying out any of their own independent research." It further alleged that these documents have been removed and deliberately withheld from them. In a letter dated March 27, 2009 addressed to the Agent for the GoS (copying the Tribunal and the PCA), the SPLM/A requested confirmation that its legal team would be granted free access to the Survey Department archive, including to those documents allegedly removed by the GoS from the archive.
55.
In a letter dated March 30, 2009 addressed to the PCA, the GoS, with reference to the Tribunal's requests dated March 17, 2000 and March 24, 2009 for complete copies of certain sketch maps/records that are within the GoS's possession or control, provided certain sketch maps requested by the Tribunal, noted that full sketch maps of certain journeys had already been provided, and explained that certain other sketch maps could not be located.
56.
In a letter dated April 1, 2009 addressed to the PCA, the GoS denied the allegations made by the SPLM/A that it did not enjoy free access to the archives and was not afforded full assistance and cooperation by the staff of the NRO and the Survey Department. The GoS explained that all documents requested by SPLM/A's legal team at the Survey Department archives were made available to them as soon as possible and that no documents were removed from the archives.
57.
The SPLM/A, by letter dated April 3, 2009 addressed to the PCA, alleged the denial of access to a significant number of documents held by the Survey Department that fall squarely within the relevant geographic area and time period central to these proceedings. It further stated that "it is impossible to determine the extent to which other materials, also directly relevant to the issues in these proceedings, continue to be withheld." The SPLM/A then stated that it will be inviting the Tribunal to infer from the GoS's failure to make available this allegedly relevant evidence and to provide satisfactory explanation for such failure, that such evidence would be adverse to the interests of the GoS in these proceedings.
58.
On April 4, 2009, through a letter from the PCA, the Presiding Arbitrator requested that the GoS respond to each point contained in the April 3, 2009 SPLM/A letter no later than 1:00PM (The Hague time), April 7, 2009.
59.
On April 7, 2009, the GoS, by letter addressed to the PCA, stated that "there has been no denial of access to the SPLM/A to the archives and nothing has been withheld. Requests could and would have been handled in time had the SPLM/A acted in a timely fashion and not made unreasonable, last-minute demands on archive staff." It emphasized that "no fact has come to light in the sketches that the SPLM/A has supplied that would justify [inferring that] the [GoS] deliberately suppress[ed] such evidence." In addition, the GoS noted that as to the introduction of new documentary evidence, "[t]he proper way under the agreed procedure for the SPLM/A to produce the new sketch maps attached to their letter would have been first to seek the leave of the Tribunal to do so. The [GoS] has no objection to the introduction of these materials which in no way advance the SPLM/A's case. The [GoS] will respond as necessary to the substance of the materials filed during the oral hearings. However, the [GoS] would hope that the agreed procedure for introducing late documents will be respected."
60.
In a letter dated April 8, 2009 addressed to the PCA, the SPLM/A alleged that the GoS's account of the factual occurrences between March 25 and 31, 2009 in its letter dated April 7, 2009 was inaccurate. It claimed that the GoS's conduct gave rise to certain inferences, and that "the SPLM/A will indicate in the course of its oral presentations where such inferences should be drawn."
61.
On April 11, 2009, the Tribunal issued the following communication to the Parties through the PCA:

The Tribunal thanks the Government of Sudan ("GoS") for its letter dated April 7, 2009 pursuant to the Presiding Arbitrator's request for comment (contained in the PCA's letter dated April 4, 2009), and acknowledges with thanks the letter dated April 8, 2009 from the Sudan People's Liberation Movement/Army ("SPLM/A"). Both these letters relate to allegations that the SPLM/A continues to be denied full access to the Archives of Sudan, that "it is impossible to determine the extent to which other materials, also directly relevant to the issues in these proceedings, continue to be withheld," and that the SPLM/A "will be" inviting the Tribunal to draw certain adverse inferences from the GoS'alleged conduct (pp. 2-3, SPLM/A letter dated April 3, 2009; see also p. 2, SPLM/A letter dated April 8, 2009).

The Tribunal notes that the SPLM/A is not asking the Tribunal to issue a ruling now and to draw any adverse inferences on account of the GoS'alleged conduct. In effect, the SPLM/A has put the GoS on notice about the adverse inferences that the former will seek from the Tribunal over the course of their argument during the oral pleadings. Accordingly, at this juncture in the proceedings, the Tribunal will take all the arguments made thus far by the Parties under advisement and has decided to remain seized of the issue. In light of the arguments presented at the oral pleadings, the Tribunal will decide, in the fullness of these proceedings, whether any adverse inferences or other appropriate conclusions should be drawn.

62.
At the oral pleadings, the GoS reiterated its commitment to ensuring that the Tribunal is given access to all the documentary records the Tribunal may require. It repeated its assertion that it did not fail in disclosing relevant documents.4

H. ALLEGATIONS OF WITNESS INTIMIDATION

63.
The GoS, by letter dated March 30, 2009 addressed to the PCA, informed the Tribunal that a news item on March 29, 2009 in the Sudanese daily newspaper Al-Ayam alleged that one of the Ngok Dinka witnesses for the GoS, Mr. Majid Yak, Secretary of Local Administration of Abyei, was threatened with being "physically eliminated" by members of the SPLM/A if he were to leave for The Hague to testify at the hearings. In addition to Mr. Yak, the GoS further claimed that, upon inquiry, its other Ngok Dinka witnesses, Messrs. Zakaria Atem, Majak Matit and Ayom Matit admitted to being repeatedly harassed by SPLM/A members either to deter them from testifying at the hearings or to convince them to change their testimony.
64.
The SPLM/A, by a letter of the same date addressed to the PCA, denied such allegations but nevertheless endeavored to investigate the allegations further and to inform the Tribunal as soon as relevant information became available.
65.
On April 14, 2009, the SPLM/A issued a letter to the PCA stating that it had investigated the allegations reported by the Sudanese press and found these to be without basis. To substantiate its claim, the SPLM/A attached to its letter a report from Lt. Col. Mayen Tap Mayen, the Chief Executive Officer of the National Security and Intelligence Organ of the Abyei Security Unit who investigated the incident, and a letter from Nyol Pagout Deng Ayei, Chief of the Bongo Chiefdom.
66.
At the oral pleadings, a member of the Tribunal, H.E. Judge Awn Al-Khasawneh, asked four witnesses of the GoS to testify whether they were intimidated by agents of the SPLM/A. The witnesses Mr. Zakaria Atem Diyin Thibek Deng Kiir,5 Mr. Majid Yak Kur,6 Mr. Ayom Matit Ayom,7 and Mr. Majak Matet Ayom8 gave varying answers.

I. REQUEST FOR FUNDING

67.
By letter to the PCA dated April 7, 2009, the SPLM/A informed the Tribunal that the Presidency of the Republic of Sudan had allegedly not yet provided any portion of a US$1,000,000 sum previously requested as funding for the SPLM/A's costs. Further, the SPLM/A stated that on March 24, 2009, it was informed by the Presidency of the Republic of Sudan that only US$200,000 of the requested US$1,000,000 would be allocated to it, and to date, it had not received any portion of this allocated amount. In view of the impending hearings, the SPLM/A requested that the Tribunal order, pursuant to the Arbitration Agreement, that the GoS "direct the Presidency [of the Republic of Sudan] to approve and transfer the funding required by the SPLM/A as a matter of urgency."
68.
Through the PCA's letter of April 8, 2009, the Presiding Arbitrator requested that the GoS comment on the allegations contained in the SPLM/A letter dated April 7, 2009 by April 9, 2009.
69.
Replying to the Presiding Arbitrator's request, the GoS, by letter addressed to the PCA on April 9, 2009, explained that the Parties had previously agreed on the procedure to be used for the allocation of funds, i.e., "joint requests [had to be made by] the Parties to the Presidency [of the Republic of Sudan.]" The GoS maintained that this procedure should be followed by both the SPLM/A and the GoS for any further requests for disbursements. The GoS also asserted that it had already provided a $200,000 allocation to the SPLM/A.
70.
On April 11, 2009, the Tribunal issued the following communication:

The Tribunal thanks the Government of Sudan ("GoS") for its letter dated April 9, 2009 pursuant to the Presiding Arbitrator's request for comment (contained in the PCA's letter dated April 8, 2009) on the Sudan People's Liberation Movement/Army's ("SPLM") request "that the Tribunal order pursuant to the Abyei Arbitration Agreement that the Government of Sudan [] direct the Presidency to approve and transfer the funding required by the SPLM/A as a matter of urgency (p. 2, SPLM/A letter dated April 7, 2009).

The Tribunal recalls the obligation of the Presidency of Sudan to fund the "cost of arbitration from the Unity Fund" on behalf of both Parties (Article 11(1), Abyei Arbitration Agreement) and is conscious of its own obligation to ensure that the parties are treated with equality and that at any stage of the proceedings, each party must be given a full opportunity to present its case (Art. 15, PCA Rules). To realize this, and to ensure the integrity of this arbitral process, the Tribunal believes that adequate funding on the part of both Parties is critical. Considering the complexity of this case, its compressed schedule and lengthy submissions, and the critical stage that these proceedings are currently in (among other factors), the Tribunal believes that the amount of US$1,000,000 requested by the SPLM/A is reasonable and should immediately be released. The Tribunal therefore expects that the GoS will facilitate and ensure the immediate release by the Presidency of the Republic of Sudan of the US$1,000,000 in funding sought by the SPLM/A on or before April 14, 2009, and to confirm to the Tribunal no later than April 13, 2009 that the process of transmitting the funds has begun.

71.
By letter dated April 13, 2009 addressed to the PCA, the GoS confirmed that the requested US$800,000 had been transferred to the account of SPLM/A while reiterating that US$200,000 had previously been transferred.
72.
On April 14, 2009, the SPLM/A wrote to the GoS, claiming that it had not received any part of the US$1,000,000 allocated to them, and that such funds were needed "as a matter of urgency."
73.
On April 15, 2009, the GoS wrote the SPLM/A, attaching the bank transfer note for US$800,000 dated April 13, 2009. The GoS explained that the US$200,000 was also previously transferred, and the bank transfer note "is being currently traced."

J. APPOINTMENT OF EXPERTS

74.
By letter dated March 10, 2009, the PCA informed the Parties that:

Mindful of the stringent time limitations established by Article 4.3 and Article 9.1 of the Arbitration Agreement, the Tribunal has requested, without prejudice of any kind, that the PCA make enquiries as to the availability of possible cartographers and geographers in the event that their assistance might be required for preparation of the Award. Arranging beforehand for the possibility of such assistance (which is envisaged under Article 27 of the PCA Rules) would enable the Tribunal to operate within the prescribed time limits, were it to make a determination under Article 2(c) of the Arbitration Agreement. Such an outcome can in no way be predicted at this stage of proceedings, but such enquiries are being made only out of prudent caution in light of the time restrictions imposed by the Parties' Arbitration Agreement.

75.
On April 2, 2009, the PCA sent the following communication to both Parties:

As indicated in [...] the PCA's letter dated March 10, 2009, the PCA has, at the Tribunal's request, made enquiries as to the availability of experts in the event and to the extent that their assistance might be required for the preparation of the Award (which can in no way be predicted at this stage). Having reviewed a number of potential candidates, the Tribunal has decided to appoint Messrs Bill Robertson and Douglas Vincent Belgrave to serve as experts in this arbitration. The CVs of Messrs Belgrave and Robertson are attached for your information.

The experts were appointed at this stage in the proceedings to enable the Tribunal to operate within the time limits prescribed by the Parties' Arbitration Agreement.

The Tribunal has instructed the PCA to circulate to the Parties the attached draft Terms of Reference, which articulates the role the Tribunal envisages for the experts within this Arbitration. The Tribunal invites the Parties to submit any comments they may have on the draft Terms of Reference no later than April 8, 2009.

76.
After receiving responses from both Parties, on April 9, 2009, the PCA communicated to both Parties that it had received no comments on the draft terms of reference.
77.
On April 16, 2009, the Tribunal issued Procedural Order No. 2, the operative part of which provides:

THE TRIBUNAL UNANIMOUSLY ORDERS:

That Messrs. Douglas Vincent Belgrave and Bill Robertson be appointed to serve as experts and provide assistance to the Arbitral Tribunal in this arbitration;

That the attached Terms of Reference for the experts be adopted.

EXPERTS' TERMS OF REFERENCE

THE EXPERTS

2.1 Messrs Bill Robertson and Douglas Vincent Belgrave (the "Experts") shall serve as experts to assist the Tribunal in accordance with these Terms of Reference.

2.2. The Experts hereby declare that they will, as directed by the Tribunal, perform their duties honorably and faithfully, impartially and conscientiously, and will refrain from divulging or using, outside the context of the tasks to be performed by them in this arbitration, any confidential documents, files and information, including the deliberations of the Tribunal, which may come to their knowledge in the course of the performance of their task.

SCOPE

3.1. The Experts shall assist the Tribunal, should it determine that the ABC experts exceeded their mandate pursuant to Article 2(a) of the Arbitration Agreement, in defining (i.e. delimiting) on a map the boundaries of the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905, in accordance with Article 2(c) of the Arbitration Agreement.

3.2. The Experts will also make themselves available to assist the Tribunal as required by it in the preparation of the Award.

3.3 The Experts shall perform their duties according to best international practices in their fields of expertise.

K. ORAL PLEADINGS PHASE OF THE PROCEEDINGS

78.
On April 7, 2009, the Tribunal issued Procedural Order No. 1, setting forth the time and place of oral pleadings, the procedure to be followed, the witnesses to be examined, and the daily agenda. The schedule allocated equal time as between the issues specified in Article 2 of the Arbitration Agreement and allocated equal time as between the Parties.
79.
On the matter of Arabic/English and Dinka/English translation, on April 8, 2009, the Tribunal issued the following communication following consultation with the Parties:

The Permanent Court of Arbitration ("PCA") acknowledges electronic receipt of letters dated April 6 and April 7, 2009 from the Government of Sudan ("GoS"), and a letter dated April 7, 2009 from the Sudan People's Liberation Movement/Army ("SPLM/A"), all relating to the Parties' commitment to determine the appointment of Dinka and Arabic interpreters for the oral pleadings.

On Arabic-English and English-Arabic interpretation, the PCA notes that the Parties have agreed to the appointment of Mr. Yahia Mo'lla Mofarih as interpreter. The PCA would appreciate being furnished with a copy of Mr. Mofarih's CV and contact details.

On Dinka-English and English-Dinka interpretation, the PCA notes that the Parties have not agreed to any appointment. The GoS proposes Mr. Abingo Akok Kshwal, while the SPLM/A proposes Messrs. Charles Deng Majok and Kwaja Yai Kuol Arop.

After consultations with the Presiding Arbitrator, the PCA has determined that each Party may employ its own Dinka-English/English-Dinka interpreter(s) for the examination of its witnesses (for example, Dinka interpretation for each of the relevant GoS witnesses' direct, cross, re-direct, and re-cross examinations shall be conducted by Mr. Abingo Akok Kshwal). Any corrections to the Court Reporter's transcription arising from a perceived error in translation may be brought to the Tribunal's attention no later than one week from the conclusion of the oral pleadings, i.e., April 30, 2009.

80.
On April 16, 2009, the PCA issued the following press release concerning the availability of a live webcast of the oral pleadings for interested members of the public:

In the matter of an arbitration pursuant to the Arbitration Agreement between the Government of Sudan and the Sudan People's Liberation Movement/Army on Delimiting Abyei Area, oral pleadings will be held at the Peace Palace in The Hague from April 18 to April 23, 2009. The oral pleadings will be open to the public and the media, and will be webstreamed live on the Permanent Court of Arbitration ("PCA") website beginning at 9:30 am (CET) on April 18, 2009 (http://www.pca-cpa.org/showpage.asp?pag id=1306).

The PCA International Bureau is acting as Registry and providing administrative support to the Arbitral Tribunal, which is composed of the following members:

Professor Pierre-Marie Dupuy (Presiding Arbitrator)

H.E. Judge Awn Al-Khasawneh

Professor Gerhard Hafner

Professor W. Michael Reisman

Judge Stephen Schwebel

The Parties have agreed to make the pleadings, transcripts, decisions and certain other documents public. These are available at the PCA website.

The PCA was established by treaty in 1899 and is the oldest intergovernmental organization devoted to the peaceful resolution of disputes through arbitration in the world. Its seat is at the Peace Palace, The Hague, The Netherlands. Further information on the PCA is available at http://www.pca-cpa.org.

81.
Pursuant to Article 8.4 of the Arbitration Agreement, public hearings were held from Saturday, April 18, 2009 until Thursday, April 23, 2009 at the Great Hall of Justice, the Peace Palace, The Hague. The attendees were:

The Tribunal:

1. Professor Pierre-Marie Dupuy

2. Judge Awn Al-Khasawneh

3. Professor Dr. Gerhard Hafner

4. Judge Stephen M. Schwebel

5. Professor W. Michael Reisman

For the Registry:

1. Mr. Aloysius Llamzon

2. Mr. Paul-Jean Le Cannu

3. Mr. Dirk Pulkowski

4. Ms. Catherine Quinn

5. Ms. Genevieve Reyes

6. Ms. Evelien Pasman

7. Ms. Gaelle Chevalier

8. Ms. Willemijn van Banning

9. Mr. Paulo Perassi

10. Mr. Thomas Levi

For the GoS:

Agent :

1. Ambassador Dirdeiry Mohamed Ahmed

Co-Agents :

2. Dr. Faisal Abdel Rahamn Ali Taha

3. Dr. Abdelrahman Ibrahim Elkhalifa

Counsel and Advocates :

4. Professor James Crawford SC

5. Professor Alain Pellet

6. Mr. Rodman R. Bundy

7. Ms. Loretta Malintoppi

8. Prof. Nabil Elaraby

Legal Advisors :

9. Ms. Angelynn Meya

10. Mr. Jacques Hartmann

11. Ms. Céline Folsché

12. Mr. Paul Baker

13. Mr. Charles Alexander

Witnesses & Expert :

14. Ayom Matet Ayom

15. Zakaria Atem Diyin Thibek Deng Klir

16. Mukhtar Babu Nimir

17. Majak Matit Ayom

18. Majid Yak Kur

19. Mr. Alastair MacDonald

Technical Advisors :

20. Mr. Martin Pratt

21. Ms. Eleanor Scudder

Other :

Representatives of the Government of Sudan

22. General [Rtd] Mahdi Babo Nimir Ali, Former Chief of Staff

23. Fathi Khalil Mohamed, Chairman Sudan Bar Association

24. Abd Elgadir Monim Mansour Mohamed, MP, Hamar Paramount Chief

25. Mohamed Aldoreek Bakht, Commissioner

26. Fadlalla Burma Nasir, Deputy Chairman, Umma Party

27. Elkheir Elfahim Elmaki Hamid, Chairman, Kordofan Reconciliation Committee

28. Mariam Elsadig Elsiddig Almahdi, Political Secretary, Umma Party

29. Safieldin Galaleldin Gibreil Omer, Member, CPA Evaluation Commission

30. Siddig El Hindi, Secretary General UDP

31. Hasan Kantabai, Political Bureau, East Sudan Front

32. El Bagir Ahmed Abdalla, Political Bureau, UDP

33. Dr. El Tayeb Haj Atia, All Sudan Initiative

34. Hussein Braima Elnour Algozuli

35. Azhari Mohamed Summo Shaaeldin

36. Sami Eldai Bushara Goda

Interested Persons And Non-Testifying Witnesses

37. Herika Iz-Aldin Humeda Khamis, Former Governor

38. Ahmed Assalih Sallouha, Former Governor

39. Rahma Abdel Rahman El-Nour, Abyei D/Chief Administrator

40. Yahia Hussain Babiker, Director, Unity Fund

41. Salman Suliman El-Safi, State Minister

42. Prof Abdalla El Sadig, Director Survey

43. Kabbashi Eltom Kabbashi

44. Ashahab Elsadig Daif Allah

45. Mohammed Mahmoud Rajab Elradi

46. Deng Balaiel Bahar Hamadean

47. Mohamed Basheir Adam Elmoalim

48. Saeed Mohammed Bakkar Degais

49. Khalid Ibrahim Ali Ibrahim

50. Maria Mayut Ayoak Gweing

51. Ahmed Abdalla Adam

52. Abdelrahman Mukhtar Hassab Alla

53. Hamadi Ad'dood Ismael Hammad

54. Abd Elgaleel Bakkar Ismail Elsakin

55. Shummo Hurgas Marida

56. Ali Hmdan Kir

57. Alsadig Ibrahim Ahmed Ibrahim

58. Hamid Bushra Godat Mohamed

59. Mohamed Elnil Mohamed

60. Hassan Mohamed Ibrahim

61. Daoud Mohamed Abdalla

62. Bashtana Mohammed Salem Suliman

63. Yagoub Abuelgasim Touri Yagoub

64. Adil Hassan Abdelrahman Mohamed

65. Abdelmonm Musa Elshiwen Aldaif

66. Ismail Hamdean Humaidan

67. Elnazir Gebreil Elgouni Abdelaziz

68. Ogeil Godtalla Abdelhamid Khamis

69. Gadim Mohamed Azaz Gamaella

70. Abdelrahman Hasan Omer

71. Abdulrahman Salih El Tahir

72. Dr. Hassan Abdin

73. Prof. Yousuf Fadl

74. Mr. Abdel Rasoul Elnour

75. Mr. Mahdi Babo Nimir

76. Dr. Suliman Eldabalo

Members of the Media

77. Hassan Makki Mohamed Ahmed, Political Analyst

78. Elhindi Omer, Columnist

79. Ishag Ahmed Fadl Allah Elfahal, Columnist

80. Sarra Taha Mohi Aldin Mohamed, TV Crew

81. Mahgoub Mohamed Salah, Editor in Chief

82. Awad Elkarim Ahmed Mustafa, TV Crew

83. Tarig Eltegany Ballal, Journalist

84. Asma El-Suhaili, Political Analyst

85. El Tayeb Zainalabdin, Editor-in-Chief

86. Khalid El Tigani, Editor-in-Chief

87. Adil El Baz, Journalist

88. El Sir Sidahmed, Journalist

89. Adil El Biali, Journalist

90. El Sadig El Rizaigi, Journalist

91. Khalid El Mubarak, Journalist

Staff from the Embassy of the Sudan

92. H.E. Ambassador A.A. Shikh Idris

93. Minister plenipotentiary Sayed. A. Ahmed

94. Mr Chol Ajongo, Counselor

95. Mr Baha Aldien Mohamed Khamis, Agricultural Counselor

96. Mr. Abbas Mohamed Alhaj, Counselor

97. Mr Abd Alrahman Abdalla Abd Alrahman, Second Secretary

98. Miss Nada Awad Omer, Administrative Attaché

99. Mrs Awatif Osman, Financial Attaché

For the SPLM/A:

Agents

1. Dr. Riek Machar Teny

2. Dr. Luka Biong Deng

Counsel and Advocates

3. Mr. Gary Born

4. Ms. Wendy Miles

5. Dr. Paul Williams

6. Ms. Vanessa Jiménez

Legal Advisers

7. Hon. Deng Arop Kuol

8. Maj. Gen. Kuol Deim Koul

9. Hon. Arop Madut Arop

10. Ms. Bridget Rutherford

11. Mr. Anand Shah

12. Ms. Courtney Nicolaisen

13. Mr. Charlie Caher

14. Ms. Kate Davies

15. Ms. Anna Holloway

16. Ms. Daisy Joye

17. Ms. Inken Knief

18. Mr. Timothy Lindsay

19. Mr. Oliver Spackman

20. Ms. Anna-Maria Tamminen

21. Ms. Lisa Tomas

22. Mr. Kevin Mottram

23. Mr. Daniel Harris

Technical Advisors and Assistants

24. Mr. Alex Tait

25. Mr. Scott Edmonds

26. Ms. Joanne Gilpin

27. Ms. Kathleen Kundt

28. Mr. Shakeel Sameja

Witnesses & Experts :

29. Mr. Deng Chier Agoth

30. Mr. Ring Makuac Dhel Yak

31. Professor J. A. Allan

32. Dr. Peter Poole

33. Professor Martin Daly

34. Mr. Richard Schofield

Observers

35. Mr. Paul Mayom Akec, Observer

36. Mr. Deng Alor Kuol

37. Mr. Michael Makuei Lueth

38. Mr. Ambrose Riny Thiik

39. Mr. Kuol Deng Mijok Kuol

40. Mr. Nyol Pagout Deng

41. Mr. Kuol Alor Makuac

42. Mr. Ajak Malual Beliu

43. Mr. Akonon Ajuong Deng

44. Mr. Arop Kuol Kon

45. Mr. Bagat Makuac Abiem

46. Mr. Mijok Kuol Lual

47. Mr. Belbel Chol Akuei

48. Mr. Chol Por Chol

49. Mr. Jacob Madhol Lang

50. Hon. Benjamin Majak Dau

51. Hon. Peter Beshir Gbandi

52. Hon. James Lual Deng Kuel

53. Hon. Zakaria Bol Deng

54. Hon. Mary Nyaulang

55. Hon. Kom Kom

56. Mr. Victor Akok Anei Magar

57. Mr. Juac Agok Anyaar

58. Mr. Edward Abyei Lino

59. Mr. Chol Changath Chol

60. Hon. Charles Abyei Jok

61. Hon. Nyankuac Ngor

62. Hon. Nyianawut Miyan

63. Ms. Asha Abbas Akwai

64. Dr. Zakaria Bol Deng

65. Hon. Bol Gatkuoth

66. Hon. Charles Abyei Kon

67. Mr. Michael Majak Abiem

68. Mr. Mathew Oturomoi Martinson

69. Mr. Biong Deng Kuol

70. Mr. Mangok Atem Piyin

71. Mr. Luka Chen Chen Atem

72. Mr. Ezekiel Lol

73. Ms. Apuk Ayuel

74. Mr. Daniel Jok

75. Mr. Victor Bullen Baba

76. Mr. Gordon Morris

77. Mr. Alfred Taban

78. Dr. Francis G. Nazario

79. Mr. Wilson Deng Peter

80. Mr. Akoc Wol Akoc

81. Mrs. Florence A. Andrew

82. Mr. Arkanjelo Ngoth

83. Mr. William Vito Akwar

84. Mr. Thomas Wako

85. Mr. Christopher Brale

86. Mr. Salvatore Ali

87. Mr. Majok Mading

88. Mr. Deng Biong Mijak

89. Mr. Stephen Kang Elario

90. Mr. Jeremiah Swaka Moses

91. Mr. Bella Kodi

92. Mr. Peter Makoi

93. Mr. Ali Alfred

94. Mr. Ater Andrew

95. Mr. Robert Lenny

96. Ms. Pani Lado

97. Mr. Nicknora Gongich

98. Nyanyol Mathiang

99. Mr. Miyong G. Kuon

100. Ms. Elizabeth Carlo

82.
As notified by the PCA on March 20, 2009 and March 30, 2009, and as revised in accordance with the Tribunal's instructions that "[...] all the witnesses of the GoS that have not been identified for cross-examination by the SPLM/A or inquiry by the Tribunal [...] may be excused,"9 the GoS presented the following expert and witnesses for crossexamination by the SPLM/A:

Mr. Alastair MacDonald

Mr. Zakaria Atem Diyin Thibek Deng Klir

Mr. Mukhtar Babu Nimir

83.
Pursuant to Procedural Order No. 1,10 the GoS presented the following witnesses to answer questions propounded by the Tribunal:

Mr. Ayom Matet Ayom

Mr. Majak Matit Ayom

Mr. Majid Yak Kur

84.
As notified on March 20, 2009 and March 30, 2009, the SPLM/A presented the following experts and witnesses for direct examination and for cross-examination by the GoS:11

Mr. Deng Chier Agoth

Professor J. A. Allan

Dr. Peter Poole

Professor Martin Daly

Mr. Richard Schofield

85.
In addition to the Parties' representatives, members of the public, diplomatic corps and media were in attendance at the hearings in accordance with Article 8.6 of the Arbitration Agreement. A live webcast of the oral pleadings was made available at the PCA website. Along with the webcast of the oral pleadings, transcripts of the hearing were made publicly available on the PCA's website immediately after each day of the hearing.12
86.
At the conclusion of the oral pleadings on April 23, 2009, the Tribunal declared closure of submissions in accordance with Article 8.9 of the Arbitration Agreement.

L. RENDERING OF THE FINAL AWARD

87.
Under Article 9(1) of the Arbitration Agreement, the Tribunal is required to render its final award "within ninety days from the closure of submissions," i.e., on July 22, 2009. The Tribunal is also required, under Article 9(3) of the Arbitration Agreement, to "communicate the final award to the [agents] of the Parties on the day of its rendering," and to "make public the award as of the same day."
88.
By a letter dated June 30, 2009 addressed to the PCA, the SPLM/A requested that "the [T]ribunal consider providing the [P]arties with at least one week notice of the date that the [T]ribunal intends to communicate the Award to the [P]arties" in order to allow the Parties "to put in place arrangements for communication of the Award in Abyei and wider Sudan," to "immediately implement the award," and to "educate the people of the Abyei area prior to the award, facilitate dissemination of the award, and take steps to prevent violence, enhance security, and consolidate peace in and around Abyei area at the time the award is communicated."
89.
On July 1, 2009, the Tribunal requested that the GoS provide any comments it may have on the SPLM/A's letter. The GoS, by letter dated July 7, 2009 addressed to the PCA, was "of the view that, as is normal practice, the Tribunal or the PCA [should] provide appropriate notification of the rendering of the award to the Agents of the Parties so as to enable the actual communication of the award to be made to the [Parties] in The Hague on the day of its rendering." The GoS also stated that it does not subscribe to the views expressed in the SPLM/A's letter, as the "implementation of the award is not contingent on the Parties receiving advance notice of its rendering," and that neither Party is authorized to take unilateral steps in connection with the security situation in the Abyei area. It noted that one of the points of agreement between the Parties at their recent talks in Washington, D.C. was that "the Parties agree[d] to develop a plan with assistance from [the United States of America] to facilitate dissemination of the arbitration decision at the local level in anticipation of the decision," and it was of the opinion that "it would be appropriate for such a plan to be developed and agreed, and for the agreed substantiation of [the United Nations Mission in Sudan] to be effected, with the view [of paving] the way for rendering the award in these proceedings in a conducive atmosphere."
90.
On July 9, 2009, the SPLM/A, by letter addressed to the PCA, stated that "[i]n the present context the SPLM/A does not consider it appropriate to respond to the majority of the matters raised by the [GoS] in its letter," as the purpose of its letter was "merely to propose that advance notification of the award would be helpful to the [P]arties." It explained that "the SPLM/A would be agreeable to the Tribunal convening a small meeting in the Hague at which the Award would be communicated to the [Parties] if such a meeting [would not] delay the communication of the Award."
91.
On July 10, 2009, the Presiding Arbitrator, through the PCA, issued the following communication to the Parties:

Having considered the SPLM/A's letter of June 30, 2009, the Government of Sudan's ("GoS") comments of July 7, 2009, and the SPLM/A's reply of July 9, 2009, the Presiding Arbitrator has instructed the PCA to inform the Parties of the following:

• Pursuant to Article 9(1) of the Arbitration Agreement, the final award "shall be rendered within a maximum of ninety days from the closure of submissions," i.e., no later than July 22, 2009. While Article 8(7) of the Arbitration Agreement empowers the Tribunal to extend this period for good cause, the Tribunal has not done so at present.

• The Arbitration Agreement does not explicitly provide for any ceremony or meeting at the rendering of the final award. Nevertheless, after receiving comments from the Agents of both Parties, the Tribunal finds it appropriate to conduct a formal event at the Peace Palace in The Hague on the day the award is rendered.

• Consistent with Paragraph 10.3 of the Terms of Appointment, the Tribunal invites the Parties to confer and jointly propose a date for the ceremony, together with any other particulars they may deem appropriate. The Parties are requested to report to the Tribunal on the outcome of their discussions no later than 8:00 PM (CET) on Monday, July 13, 2009. In the absence of an agreement, the Tribunal will decide the matter in due course.

92.
On July 13, 2009, both Parties informed the Tribunal that they were unable to reach agreement on this matter. The GoS, by letter dated July 13, 2009 addressed to the PCA, proposed that "the award rendering ceremony be held on [August 21,] 2009, after a reconciliation ceremony that the Government of Sudan has asked the Government of the Netherlands to organize in conjunction with the reading of the award on [August 19-20, 2009]." It explained that it is essential that the chiefs of both the Misseriya and Ngok Dinka communities be invited and be given an opportunity "to listen to the award in person," and that logistical constraints would render it impracticable to have an award ceremony before August 10, 2009. The SPLM/A, on the other hand, by letter dated July 13, 2009 addressed to the PCA, stated that "it does not wish for the communication of the Award to be delayed in any way," and that "if any delay was to result from convening a meeting in the Hague then the SPLM/A would strongly prefer that the Award simply be communicated to the Agents and their legal counsel by email."
93.
On July 14, 2009, the following communication from the Tribunal was sent by the PCA to the Parties:

Having considered the Parties' positions, the Presiding Arbitrator has instructed the PCA to inform the Parties of the following on behalf of the Tribunal:

• Due to the inability of the Parties to agree on a new date for the rendering of the award, the Tribunal considers that it must adhere to the 90-day period provided under Article 9(1) of the Arbitration Agreement. The Tribunal will therefore render its Award in a short ceremony on July 22, 2009, 10:00a.m., at the Great Hall of Justice, The Peace Palace, The Hague. The Tribunal has instructed the PCA to issue a press release today to inform members of the public accordingly.

• Consistent with Article 9(3) of the Arbitration Agreement, the Tribunal invites the Agents and counsel of the Parties to be present at the awardrendering ceremony, along with any number of party representatives they deem appropriate. While the Parties are free to compose their respective delegations as they see fit, the Tribunal extends a particular invitation to the chiefs of the Misseriya and Ngok Dinka communities to be present at the ceremony. The Parties are requested to inform the PCA of the composition of their respective delegations no later than 1:00PM (CET), Monday, July 20, 2009.

• Consistent with Article 9(4) of the Arbitration Agreement, the Tribunal has also instructed the PCA to invite representatives of the States and other entities who witnessed the signing of the Comprehensive Peace Agreement, and a representative of the Assessment and Evaluation Commission, to attend the ceremony.

• Consistent with Article 8(6) of the Arbitration Agreement and the practice followed in these proceedings, the award-rendering ceremony will be made open to the public and will be webstreamed live at the PCA website. The Tribunal authorizes the Parties to invite members of the Sudanese and international media to be present at the ceremony. The Tribunal has also instructed the PCA to prepare a press release, in both English and Arabic, designed to provide a short summary of the most critical aspects of the Tribunal's award. The Press Release will be issued immediately after the ceremony.

• The Tribunal will be represented at the ceremony by the Presiding Arbitrator, who will give a brief statement summarizing the Award.

94.
On July 14, 2009, the PCA issued a press release concerning the rendering of the final award, which provides in part:

In the matter of an arbitration pursuant to the Arbitration Agreement Between the Government of Sudan and the Sudan People's Liberation Movement/Army on Delimiting the Abyei Area, the arbitral Tribunal will render its final award ("Award") on July 22, 2009, 10:00a.m. (CET; GMT +2), at the Peace Palace, The Hague.

During this ceremony, the Presiding Arbitrator will personally deliver the Award to representatives from both Parties and deliver a brief statement summarizing the Award. The ceremony will be webstreamed live on the Permanent Court of Arbitration ("PCA") website beginning at approximately 10:00 am (CET; GMT +2) on July 22, 2009 (http://www.pca-cpa.org/showpage.asp?pag_id=1306). Representatives of the States and other entities who witnessed the signing of the Parties' Comprehensive Peace Agreement have been invited to attend the ceremony. Members of the Sudanese and international media are also invited to be present.

Immediately after the ceremony, the Award will be made public through the PCA website. The PCA will also issue a press release (in both English and Arabic), which will provide a short summary of the most critical aspects of the Award.

The PCA emphasizes that until the Award is rendered at the ceremony on July 22, 2009, its contents will continue to be absolutely confidential. No person or entity has or will be given advanced notice of the Tribunal's decision.

CHAPTER II - INTRODUCTION

95.
The GoS and the SPLM/A agreed in 2004 to define the "Abyei Area" in the following terms: "The territory [of the Abyei Area] is defined as the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905."13 (In appropriate instances, this phrase is also referred to in this Award as the "Formula") However, the Parties do not agree on the boundaries of the Abyei Area that the application of that Formula should produce. It is this disagreement that constitutes the essence of the dispute submitted for arbitration to the Tribunal.

A. GEOGRAPHY

1. The Republic of Sudan

96.
The Republic of Sudan ("Sudan") is located in north-east Africa, situated between latitudes 3°53'N and 21°55'N and longitudes 21°54'E and 37°30E.14 It borders Egypt to the north, Chad, Libya and the Central African Republic to the west, the Democratic Republic of the Congo, Uganda and Kenya to the south, and Ethiopia and Eritrea to the east.15 The largest country in Africa, it comprises 2,376,000 square kilometers of land and 129,810 square kilometers of water. Below is a map of Sudan and its international boundaries:16
97.
Sudan is divided into twenty-five states, of which fifteen are located in northern Sudan ("Northern Sudan") and ten in southern Sudan ("Southern Sudan"). Northern Sudan comprises the states of Blue Nile, Gezira, Gadarif, Kassala, Khartoum, Northern, North Darfur, North Kordofan, Red Sea, Nile, Sinnar, South Darfur, South Kordofan, West Darfur and White Nile.17 Southern Sudan comprises Central Equatoria, Eastern Equatoria, Jonglei, Lakes, Northern Bahr el Ghazal, Unity, Upper Nile, Warab, Western Bahr el Gahazal and Western Equatoria.18
98.
Sudan has some 40 million inhabitants with an average population density of approximately 14 persons per square kilometer.19 There are 19 major ethnic groups and almost 600 subgroups, amounting to more than 100 languages and dialects spoken.20 In a census on ethnicity in 1956, it was reported that Arabs constituted 39 percent and Africans 61 percent of the population. Generally, the Arabs are located in Northern Sudan while the Africans are located in the South. At 12 percent of the national population, the Dinka was at that time the largest single group from Southern Sudan. 70 percent of the population reportedly follow Islam while the remainder, predominantly in Southern Sudan, follow local faiths (25 percent) or Christianity (5 percent).21
99.
The climate is arid in the north, whereas the south-west is characterized by tropical wet and dry seasons. Temperatures do not vary greatly throughout the year. However, the length of the dry season differs in various regions, dependent upon the flows of the dry, northeasterly winds from the Arabian Peninsula and moist south-westerly winds from the Congo River basin.22

2. Northern Sudan

100.
North Sudan constitutes three-quarters of the surface area of Sudan and is inhabited by the same proportion of its population, approximately 31 million people.23 The majority are Muslim, and Arabic is the dominant language. As much of North Sudan is desert, the majority of its population lives in just over 15 percent of the land.24 Some Arab tribes such as the Baggara are nomadic while others, including Ja'aliyyin and Danagla, farm along the Nile and further south.25

3. Southern Sudan

101.
Southern Sudan has an estimated population of 8.99 million and a surface area of 640,000 square kilometers.26 It is a predominantly rural, subsistence economy and is fertile throughout the year. It is served by a number of major river systems and dense tropical evergreen forests, which sustain a wide range of cereals, vegetables and tree crops.27 The largest group in South Sudan is the Dinka, comprising 12 percent of the national population, followed by the Azande and Nuer.28 The most widely-spoken languages are Dinka, Juba Arabic, Nuer and English. The SPLM/A political party holds a distinct majority in the Southern Sudan Legislative Assembly.

4. The Abyei Location, the Ngok Dinka, and the Misseriya

102.
The Abyei location is located between the north and the south of Sudan. It has been referred to by the Parties as "a bridge between the north and the south, linking the people of Sudan."29
103.
The township of Abyei ("Abyei Town") is located north of the river Bahr el Arab/Kir.30 This river runs through the adjoining provinces of Bahr el Ghazal, Darfur and Kordofan.31 The Bahr el Arab is known by other names, attributable to the different tribes living along its course.32 Thus, the Ngok Dinka refer to the Bahr el Arab as the Kir33 or the Gurf,34 while other references (including by Arabic speakers) identified the same river as "the Bar el Jange" or the "Bahr ed Deynka."35
104.
The Bahr river basin contains the Bahr el Arab/Kir, the Ngol/Ragaba ez Zarga, the Nyamora/Umm Rebeiro, and the Nam/Bahr el Gazal.36 To the south of this is the Sudd, one of the world's largest swamps.37 The clay plains of the Abyei region are characterized by thick forest, bushes, and vegetation, which combined with the extreme wet and dry seasons support the many fruits and plants which can be found there.38 There are three major oilfields in the area, whose 2005 to 2007 revenues were estimated in the region of US$1.8 billion.39
105.
As described by the SPLM/A, Abyei Town is the ancestral homeland of the Ngok Dinka.40 However, the GoS alleges that there is no documentary evidence that Abyei existed as a settlement in 1905, and claims that the earliest map that shows Abyei in its present location dates from 1916.41
106.
The Ngok Dinka, one of the 25 tribes which comprise the Dinka people,42 are reportedly a highly cohesive tribal unit of an estimated 300,000 people, with a well-defined, centralized political structure. They are divided into nine Chiefdoms, under a single "Paramount Chief":43 Abyior, Achaak, Achueng, Alei, Anyiel, Bongo, Diil, Mareng and Manyuar.44 Each Chiefdom has an area of permanent habitation and seasonal grazing areas.45 They cultivate the land46 and, through tribal law and custom, grant individuals and families exclusive right to use certain lands.47 The Ngok are said to have a spiritual connection with the land through their tribes' ancestors.48 The present-day Abyei Town is the centre of their political and commercial affairs.
107.
Living to the north of the Ngok Dinka are the Misseriya, Arab nomads who have their base in the region of Muglad.49 The Misseriya are said to be cattle-herders whose nomadic existence takes them across a wide territory, ranging from the area around Muglad in the north, where they spend much of each year, to the Bahr river system of the Abyei region during parts of the dry season.50

B. HISTORICAL CONTEXT

1. First and Second Civil Wars

108.
Sudan obtained independence on January 1, 1956. Soon thereafter civil war erupted between Northern Sudan and Southern Sudan. By 1965, the Misseriya and the Ngok Dinka were said to be participating in the civil war, with the former allied with Northern Sudan and the latter with Southern Sudan. In 1972, the civil war was ended by the Addis Ababa Agreement, which provided for a referendum to allow "any other areas that were culturally and geographically a part of the Southern Complex" to choose to remain in Northern Sudan or to join a new autonomous Southern Sudan.51
109.
However, subsequent disputes over power, resources, religion, and self-determination led in 1983 to a second civil war.52 The Abyei Area is said to be at the geographical center of this civil war, which is the longest running conflict in Africa and has caused some two million deaths, significant economic destruction and untold suffering, particularly for the people of Southern Sudan.53

2. Negotiations for Peace

(a) Machakos Protocol 2002

110.
On July 20, 2002 the Parties signed the Machakos Protocol ("Machakos Protocol"). The Machakos Protocol provided that a peace agreement was to be implemented in accordance with the sequence, time periods, and processes set out therein.54 It also provided for an internationally monitored referendum, organized jointly by the GoS and the SPLM/A, entitling the people of Southern Sudan to vote on whether to secede from Sudan.55
111.
The referendum was to be preceded by two transition phases. The first phase, the "PreInterim Period"56, would last for six months and would establish, among others: (i) a constitutional framework for the peace agreement; (ii) mechanisms to implement and monitor the Peace Agreement; (iii) if not already in force, a cessation of hostilities with appropriate monitoring mechanisms; and (iv) preparations for the implementation of a comprehensive ceasefire.57
112.
The next phase, the "Interim Period," would commence at the end of the Pre-Interim Period and last for six years.58 During this time, the institutions and mechanisms established during the Pre-Interim Period were to operate in accordance with the arrangements and principles set out in the peace agreement, and if not already accomplished, the negotiated ceasefire was to be fully implemented and put into operation.59

(b) The Abyei Protocol

113.
The Abyei Protocol ("Abyei Protocol") was signed on May 26, 2004 and provided for agreed principles in administering the Abyei Area upon signing of the peace agreement. Notably, Section 1.1.2 of the Abyei Protocol defined the territory as "the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905." The Abyei Area was to be accorded special administrative status and was to be administered by a local executive council elected by the residents of the Abyei Area.60 These residents were to be dual citizens of Western Kordofan and Bahr el Ghazal, with representation in the two legislatures.61 Residents were defined as members of the Ngok Dinka community and other Sudanese residing in the Abyei Area.62
114.
The Abyei Protocol also provided for the establishment of the ABC, which was given the task of "defin[ing] and demarcat[ing]" the Abyei Area.63

(c) The Abyei Appendix

115.
On December 17, 2004, the Parties signed an "Understanding on Abyei Boundaries Commission" ("Abyei Appendix"), which determined the composition of the ABC as follows:

(a) one representative from each of the GoS and the SPLM/A;

(b) "five impartial experts knowledgeable in history, geography and any other relevant expertise" nominated by the United States, the United Kingdom and the Inter-Governmental Authority on Development ("IGAD");

(c) two nominees of the GoS and two nominees of the SPLM/A "from the present two administrations of the Abyei Area;"

(d) two nominees of the GoS from the Messiriya; and

(e) two nominees of the SPLM/A from the "neighboring Dinka tribes to the South of the Abyei Area."64

116.
In determining the Abyei Area, the ABC was required "to listen to representatives of the people of Abyei Area and their neighbours, [as well as to] listen to presentations of the two Parties"65 and to "consult the British Archives and other relevant sources on Sudan wherever they may be available, with a view to arriving at a decision that shall be based on scientific analysis and research."66 The ABC Experts were also required to determine the rules of procedure of the ABC.67
117.
The Abyei Appendix further prescribed that the ABC should present its report to the Presidency before the end of the Pre-Interim Period, and that the "report of the [ABC Experts], arrived at as prescribed in the ABC rules of procedure" would be "final and binding on the Parties."68

(d) Comprehensive Peace Agreement

118.
On January 9, 2005, the Parties signed the Peace Agreement (the "Comprehensive Peace Agreement" or "CPA") that initiated the Pre-Interim Period.69 They reconfirmed their commitment to the following instruments previously agreed upon, which were integrated into the CPA: the Machakos Protocol, the Protocol on Security Arrangements of September 25, 2003, the Protocol on Wealth-Sharing of September 25, 2003, the Protocol on PowerSharing of May 26, 2004, the Protocol on the Resolution of Conflict in Southern Kordofan and the Blue Nile States of May 26, 2004 and the Abyei Protocol (with its annex, the Abyei Appendix).70

(e) Interim National Constitution

119.
Subsequently, on July 6, 2005, the Sudanese National Assembly adopted the Interim National Constitution of the Republic of Sudan ("Interim National Constitution"). This Constitution recognized the commitment of Sudan to comply with the CPA71 and to give constitutional support to the Abyei Protocol.72

3. ABC Terms of Reference and Rules of Procedure

120.
The Parties met in Nairobi between March 10-12, 2005 to draw up the Terms of Reference, which documented a "joint understanding [of] all the issues" by the Parties.73 The Terms of Reference contain the Parties understanding of the "Mandate," the "Structure" of the ABC, the "Functioning of the ABC," the "Program of work" and "Funding."
121.
The Rules of Procedure were drawn up by the ABC Experts74 and approved by the Parties on April 11, 2005. The Rules of Procedure set forth, among other matters, the schedule to be followed by the ABC Experts and the method to be followed for public meetings and field visits. The Rules of Procedure also provided that the ABC Experts would "examine and evaluate all the material they have gathered and will prepare the final report."75 They also state that "[the] Commission will endeavour to reach a decision by consensus," but if "an agreed position by the two sides is not achieved, the [ABC Experts] will have the final say."76

4. ABC Experts' Report

122.
The ABC Experts officially presented their report ("ABC Experts' Report" or "Report") to the Sudanese Presidency on July 14, 2005. The ABC Experts' Report was signed by the ABC Experts, namely, Ambassador Donald Petterson (as Chair), Professor Kassahun Berhanu, Professor Shadrack B. O. Gutto, Dr. Douglas H. Johnson and Professor Godfrey Muriuki.
123.
The ABC Experts' Report notes that the ABC Experts listened to presentations from the GoS and the SPLM/A and heard testimony from "Sudanese in Abyei Town, areas to the northeast and northwest of there, Agok and Muglad" as well as to "a group of Ngok Dinka living in Khartoum and a group of Twich Dinka residing there."77 The formal testimonies of 104 persons (47 Dinka and 57 Misseriya) were given under oath in public meetings. Witnesses and a large non-witness audience were reportedly able to listen to the testimony as they were being given.78
124.
In the Preface to the ABC Experts' Report, the ABC Experts explained their process of research:

No map exists showing the area inhabited by the Ngok Dinka in 1905. Nor is there sufficient documentation produced in that year by the Anglo-Egyptian Condominium government authorities that adequately spell out the administrative situation that existed in that area at that time. Therefore, it was necessary for the [ABC Experts] to avail themselves of relevant historical material produced both before and after 1905, as well as during that year, to determine as accurately as possible the area of the nine Ngok Dinka chiefdoms as it was in 1905.79

125.
Further noting that the GoS and SPLM/A presentations and oral testimony "largely contradicted each other and did not conclusively prove either side's position," the ABC Experts sought to obtain as much evidence as they could from archives and sources in Sudan, the United Kingdom, South Africa and Ethiopia, concentrating on records contemporaneous with or referring to the period of the Anglo-Egyptian Condominium (i.e. 1899-1956).80 Thus, the ABC Experts reviewed historic documents at the Sudan National Records Office, maps at the Sudan National Service Authority, and additional documents at the University of Khartoum library.81 Three of the ABC Experts traveled to England to examine additional maps and documents at the Rhodes House Library and the Bodleian Library at Oxford University, as well as at the Sudan Archive of the University of Durham. They also met former District Commissioner Michael Tibbs in Sussex and anthropologist Ian Cunnison in Hull.82 The two other ABC Experts undertook additional research in Addis Ababa and Pretoria.83
126.
The ABC Experts state that they analyzed the material applying "the generally accepted historical method of comparing oral with written material," as well as "established legal principles in determining land rights in former British-administered African territories, including the Sudan."84
127.
In conducting their research, the ABC Experts were mindful of what the official United States Government proponents of the Formula for the "Abyei Area" stated: "[I]t was clearly our view when we submitted our proposal that the area transferred in 1905 was roughly equivalent to the area of Abyei that was demarcated in later [years]."85 They maintain that "[t]his position was, according to the American participants, conveyed to the two sides at the Naivasha talks."86
128.
The GoS and the SPLM/A representatives made final presentations to the ABC on June 1617, 2005. The ABC Experts' Report states:

The Government of Sudan's position is that the only area transferred from Bahr el-Ghazal to Kordofan in 1905 was a strip of land south of the Bahr el-Arab/Kir; that the Ngok Dinka lived south of the Bahr el-Arab/Kir prior to 1905, and migrated to the territory north of the river only after coming under the direct administration of Kordofan. Therefore the Abyei Area should be defined as lying south of the Bahr el-Arab/Kir, and excluding all territory to the north of the river, including Abyei Town itself. This is opposed by the SPLM/A position which is that the Ngok Dinka have established historical claims to an area extending from the existing Kordofan/Bahr el-Ghazal boundary to north of the Ragaba ez-Zarga/Ngol, and that the boundary should run in a straight line along latitude 10°35'N87

129.
The ABC Experts completed their deliberations on June 20, 2005.88 The ABC Experts' Report was presented to the Sudanese Presidency on July 14, 2005.
130.
The ABC Experts made the following determinations in the "Conclusions" section of the ABC Experts' Report:

• In 1905 there was no clearly demarcated boundary of the area transferred from Bahr el-Ghazal to Kordofan;

• The GOS belief that the area of the nine Ngok Dinka chiefdoms placed under the authority of Kordofan in 1905 lay entirely south of the Bahr el-Arab is mistaken. It is based largely on a report by a British official who incorrectly concluded that he had reached the Bahr el-Arab when in fact he had only come to the Ragaba ez-Zarga/Ngol. For several years afterwards maps, some of which were cited by the GOS in its presentation to the ABC Experts, manifested this error;

• The Ngok claim that their boundary with the Misseriya should run from Lake Keilak to Muglad has no foundation;

• The historical record and environmental factors refute the Misseriya contention that their territory extended well to the south of the Bahr el-Arab, an area to which they never made a formal claim during the Condominium period;

• Although the Misseriya have clear "secondary" (seasonal) grazing rights to specific locations north and south of Abyei Town, their allegation that they have 'dominant' (permanent) rights to these places is not supported by documentary or material evidence;

• There is compelling evidence to support the Ngok claims to having dominant rights to areas along the Bahr el-Arab and Ragaba ez-Zarga and that these are long-standing claims that predated 1905;

• There is no substance to the Misseriya claim that because the Abyei Area was included in 'Dar Messeria' District, it belongs to the Misseriya people. The Ngok and the Humr were put under the authority of the same governor solely for reasons of administrative expediency in 1905. After that action, the Ngok retained their identity and control over their local affairs and maintained a separate court system and hierarchy of chiefs;

• The administrative record of the Condominium period and testimony of persons familiar with the area attest to the continuity of Ngok Dinka settlements in, and use of, places north of the Bahr el-Arab between 1905 and 1965, as claimed by the Ngok and the SPLM/A;

• The ABC Experts considered the presentation by the SPLM/A that their dominant claim lies at latitude 10°35' N, but found the evidence in support of this to be inconclusive; and

• The border zone between the Ngok and Misseriya falls in the middle of the Goz, roughly between latitudes 10°10' N and 10°35' N.89

131.
The "Final and Binding Decision" of the ABC Experts' Report is as follows:

1) The Ngok have a legitimate dominant claim to the territory from the Kordofan-Bahr el-Ghazal boundary north to latitude 10°10' N, stretching from the boundary with Darfur to the boundary with Upper Nile, as they were in 1956;

2) North of latitude 10°10' N, through the Goz up to and including Tebeldia (north of latitude 10°35'N) the Ngok and Misseriya share isolated occupation and use rights, dating from at least the Condominium period. This gave rise to the shared secondary rights for both the Ngok and Misseriya;

3) The two Parties lay equal claim to the shared area and accordingly it is reasonable and equitable to divide the Goz between them and locate the northern boundary in a straight line at approximately latitude 10°22'30" N. The western boundary shall be the Kordofan-Darfur boundary as it was defined on 1 January 1956. The southern boundary shall be the Kordofan- Bahr el-Ghazal-Upper Nile boundary as it was defined on 1 January 1956. The eastern boundary shall extend the line of the Kordofan-Upper Nile boundary at approximately longitude 29°32'15" E northwards until it meets latitude 10°22'30" N;

4) The northern and eastern boundaries will be identified and demarcated by a survey team comprising three professional surveyors: one nominated by the National Government of the Sudan, one nominated by the Government of the Southern Sudan, and one international surveyor nominated by IGAD. The survey team will be assisted by one representative each from the Ngok and Misseriya, and two representatives of the Presidency. The Presidency shall send the nominations for this team to IGAD for final approval by the international ABC Experts;

5) The Ngok and Misseriya shall retain their established secondary rights to the use of land north and south of this boundary.90

132.
A map of the Abyei Area, as delimited by the ABC Experts,91 is reprinted below:

5. Abyei Road Map and Arbitration Agreement

133.
Upon the delivery of the ABC Experts' Report, disagreements arose between the Parties as to whether the ABC Experts exceeded their mandate.
134.
On June 8, 2008, the Parties signed "The Road Map for Return of IDPs and Implementation of Abyei Protocol" (the "Abyei Road Map") in Khartoum. Through the Abyei Road Map, the Parties committed, among other matters, to refer this dispute to arbitration, and to "abide by and implement the award of the arbitration tribunal."92 They also agreed, without prejudice the outcome of the arbitration, on interim boundaries for the Abyei Area for administrative purposes.93
135.
The Abyei Road Map's agreement to arbitrate was implemented shortly thereafter through the Arbitration Agreement, which was signed on July 7, 2008.

CHAPTER III - SUMMARY OF THE PARTIES' ARGUMENTS

136.
Consistent with Article 2 of the Arbitration Agreement and the Parties' presentations at the oral pleadings, this chapter is organized into two sections: (1) the Parties' arguments on whether the ABC Experts exceeded their mandate, and (2) the Parties' arguments concerning the delimitation of the Abyei Area.

A. EXCESS OF MANDATE

137.
This section summarizes the Parties' arguments relating to whether the ABC Experts had "exceeded their mandate." As the GoS claims such excess of mandate and the SPLM/A's arguments on this matter are mostly cast in response to the GoS's contentions, the summary will be primarily organized using the framework contained in the GoS Memorial.94

1. "Excess of Mandate" Conceptions

138.
Article 2(a) of the Arbitration Agreement provides that the Tribunal is to determine, at the outset:

[w]hether or not the ABC Experts had, on the basis of the agreement of the Parties as per the CPA, exceeded their mandate which is "to define (i.e. delimit) and demarcate the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905" as stated in the Abyei Protocol, and reiterated in the Abyei Appendix and the ABC Terms of Reference and Rules of Procedure. (emphasis added)

139.
There is disagreement between the Parties on the content and meaning of "excess of mandate" within the context of these proceedings. The GoS contends that the phrase should be interpreted in its ordinary meaning, given that the Parties did not agree on any special meaning.95 The GoS would liken the phrase to the concepts of "excess of jurisdiction," decisions taken ultra vires or decisions involving an excess of power ( exces de pouvoir)96 The GoS maintains that exces de pouvoir has always been interpreted as including all serious misuses of jurisdiction as well as gross violations of procedural rules.97 The GoS thus asserts that "if the ABC Experts exceeded their mandate in any respect, this is sufficient to trigger Article 2(c) of the Arbitration Agreement."98
140.
The SPLM/A, on the other hand, contends that an "excess of mandate" is a specific, identifiable type of defect,99 which is already particularly defined by Article 2(a) of the Arbitration Agreement by reference to that category of disputes which the Parties submitted to the ABC ("their mandate WHICH IS... ").100 Taking this definition into consideration, an "excess of mandate" would be narrower than the GoS's conception (which includes an exces de pouvoir)101 and would be confined to a decision ultra petita102, i.e., a decision that went beyond the ambit of the issues argued by the parties. The SPLM/A also believes that this reading would be in line with the more contemporary understanding of "excess of mandate."103

2. Procedural Excess of Mandate Arguments

(a) Preliminary Argument: Procedural Excesses as a Basis for Claiming Excess of Mandate

(i) GoS Arguments

141.
The GoS places emphasis on the fact that the Parties took care in drafting Terms of Reference according to which the ABC Experts were obliged to carry out their mandate. The ABC Experts also drew up Rules of Procedure to guide their proceedings. If the ABC Experts materially deviated from the Terms of Reference and Rules of Procedure in carrying out the task conferred on them, the GoS maintains that this would be inconsistent with the conditions laid down for the exercise of their mandate.104 The specific inclusion by the Parties of the Terms of Reference and Rules of Procedure in Article 2(a) of the Arbitration Agreement105 is said to be evidence of the importance the Parties placed on these instruments, and confirms their intention to incorporate any serious procedural violation within the Tribunal's mandate.106
142.
The GoS also contends that the ABC Experts were not endowed with broad procedural discretion. Citing Section 5 of the Abyei Appendix,107 the GoS maintains that the Parties premised the final and binding character of the ABC Experts' Report on the proper application of the Rules of Procedure.108 The GoS also emphasizes that the procedural rules apply to the ABC as a whole, not to the ABC Experts in isolation. The fact that the essential tasks were assigned to the Commission as a whole and not to the ABC Experts alone was a guarantee of transparency and of equality in the Parties' treatment. Insofar as the ABC Experts worked separately without notice to the Parties, these guarantees have been ignored and a fundamental rule of procedure has been violated.109 Such serious procedural irregularities are grounds for an excess of mandate, as recognized by numerous international conventions and instruments.110

(ii) SPLM/A Arguments

143.
The SPLM/A rejects any reading of Article 2(a) of the Arbitration Agreement111 that would permit the ABC Experts' Report to be challenged based on purported violations of "procedural conditions" or procedural rights, as the scope of the Tribunal's review pursuant to Article 2(a) is narrowly defined;112 the "mandate" of the ABC, which the Tribunal must analyze for purported excess, is "to define (i.e. delimit) and demarcate the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905." Further, the formulation makes no reference to violations of the ABC Rules of Procedure or any other arbitration procedures and reading these into the provision would be impermissible.113
144.
Moreover, the SPLM/A asserts that the ABC was a sui generis body with a unique set of procedures intended to give the ABC Experts the freedom to conduct the proceedings as they thought fit;114 there were very few mandatory procedural restrictions on the ABC Experts.115 The ABC Experts were recognized by both Parties as experts in history, geography, culture, and African law and were called upon to apply the procedures of "scientific analysis and research."116 They were not international arbitration practitioners and were not subject to rules of procedural conduct based on arbitral principles.117
145.
Citing a number of authorities, the SPLM/A also contends that a dispute regarding "jurisdiction" or excess of mandate does not extend to procedural complaints.118 The SPLM/A further emphasizes that a party seeking to invalidate an arbitral award or other adjudicative decision on procedural grounds must show serious prejudice, such that the Tribunal would have decided otherwise had the Tribunal not made the particular mistake.119 It contends that the GoS has not satisfied its burden of proof in this respect.120

(b) The ABC Experts Allegedly Took Evidence from Ngok Dinka Informants without Procedural Safeguards and without Informing the GoS

(i) GoS Arguments

146.
The GoS maintains that the ABC Experts arranged three unscheduled meetings with Ngok Dinka informants at the Hilton Hotel, Khartoum without informing it.121 Because the Terms of Reference were said to be unusually detailed and specific with respect to the ABC Experts' conduct in relation to oral testimony,122 and carefully distinguished between acts of the ABC as a whole and that of the ABC Experts, those terms must be taken seriously.123
147.
The GoS points out that a meeting could have been arranged in Khartoum either with or without the Parties (i.e., by the ABC Experts alone), provided that the Parties consented and appropriate safeguards were instituted. However, instead of approaching the Parties prior to holding meetings in Khartoum, the ABC Experts allegedly took it upon themselves to convene meetings without the knowledge of the GoS. On April 21, 2005, the ABC Experts had a "secret meeting" with Ngok Dinka informants at the Hilton Hotel, Khartoum. This meeting was followed by two additional unscheduled meetings on May 6 and 8, 2005.124 At these meetings, the GoS alleges that the ABC Experts obtained maps and other documents that were never shown to the Parties, even though some of these materials were used in the preparation of the ABC Experts' Report.125
148.
The GoS also claimed that on April 25, 2005, the ABC Experts issued a note to the Commission detailing the testimony they obtained during their field visits and informed the Commission of their decision to stop collecting oral testimony and to resort to archival research. The GoS found it disturbing that the note did not mention the Hilton meeting on April 21, 2005, nor did their alleged decision deter them from scheduling the subsequent May 6 and May 8 meetings.126
149.
By arranging interviews without the knowledge of the Parties, the GoS argues that the ABC Experts not only deliberately circumvented the agreed work program, they also demonstrated a propensity to side with the SPLM/A and thus deprived the GoS of the right to a fair procedure. This is especially so since no information of these meetings was provided to the GoS until the final presentation of the ABC Experts' Report. Because a serious departure from a fundamental rule of procedure constitutes, in the view of the GoS, a ground for finding an excess of mandate, the taking of evidence by the ABC Experts without procedural safeguards and without informing the GoS constitutes an excess of mandate.127

(ii) SPLM/A Arguments

150.
The SPLM/A asserts that the agreed framework regarding the ABC proceedings imposed no prohibition on meetings between the ABC Experts and additional members of the public.128 On the contrary, Section 7 of the ABC Rules of Procedure is said to expressly ensure that the ABC members - and not just the entire Commission - would be able to conduct such meetings if they chose129 without any prior notice requirement.130 The Parties' express contemplation was to allow the ABC Experts to conduct their own independent investigations, and to consult "other relevant sources,"131 rather than being dependent on the Parties to present testimony or information to them.132 The SPLM/A also maintains that, in fact, the GoS was informed about the ABC Experts' meetings with both Ngok Dinka and Twic Dinka members133 in Khartoum, that no objections were raised,134 and that this objection should be thus considered waived.135
151.
Even assuming that a violation of procedural rules did occur, the SPLM/A maintains that any such breach does not rise to the level of a "serious departure from a fundamental rule of procedure."136 In their view, any breach of procedure needs to be considered within the context of the ABC Experts' broad, independent investigative authority and the ABC Experts' wide procedural discretion, and the deliberately informal and non-technical nature of the ABC proceedings.137 At most, any violation would have been an unintentional omission inconsistent with implied provisions of the ABC Experts' own procedural rules, which they were free to alter or amend.138
152.
Finally, the SPLM/A believes that these meetings caused no prejudice to the GoS because they did not alter the outcome of the ABC Experts' decision. Quoting the GoS's acknowledgment that procedural breaches must be material, both in themselves and as to the result reached,139 the SPLM/A maintains that the person who arranged the meeting and the witnesses interviewed in Khartoum were likely to be supporters of the GoS's position on the Abyei Area or to testify on Dinka matters that had little to do with the question at hand.140 Moreover, the only map that was recorded as being given to the ABC Experts during the meetings (described as a copy of a sketch map) was not relied upon in the final decision.141 Finally, the SPLM/A sought to clarify that the April 25, 2005 note on testimony issued by the ABC Experts related to field visits between April 14 and April 20, 2005, before the contentious meetings took place.142

(c) The ABC Experts Allegedly Unilaterally Sought and Relied on the Millington E-mail, without Notice to the GoS, to Establish Their Interpretation of the Formula

(i) GoS Arguments

153.
The GoS alleges that, to establish their interpretation of the Formula, the ABC Experts unilaterally sought and then relied on an e-mail from an official at the Embassy of the United States of America in Nairobi, Mr. Jeffrey Millington. The response in question from Mr. Millington, which purportedly set out the US Government's understanding of the Formula, was:

It was clearly our view when we submitted our proposal [that] the area transferred in 1905 was roughly equivalent to the area of Abyei that was demarcated in later years.143

154.
The GoS argues that such unilateral actions involved a serious departure from a fundamental rule of procedure in three distinct ways:

(a) The ABC Experts were not authorized to consult the US Government nor any other third party.144 Mr. Millington's e-mail allegedly had nothing to do with the "independent investigations and scientific research" that the ABC Experts were supposed to conduct.145

(b) The Parties were given no notice of the request or the response and thus had no opportunity to comment. This was, in the GoS's view, a clear failure of due process and a patent breach of Section 14 of the Rules of Procedure.146

(c) The ABC Experts failed to see that Mr. Millington's response raised more questions than it resolved. The GoS sees no relation between "the area of the nine Ngok Dinka Chiefdoms transferred to Kordofan in 1905" and "the area of Abyei that was demarcated in later years."147

155.
The GoS contends that Mr. Millington's e-mail affected the outcome of the ABC decision, as it strengthened the ABC Experts' manifestly wrong interpretation of the substance of their mandate: in the ABC Experts' Report, mention of the disputed e-mail immediately succeeds the interpretation of the Formula by the ABC Experts, from which the word "transferred" had been carefully deleted.148

(ii) SPLM/A Arguments

156.
In the SPLM/A's view, the Parties' procedural agreements and the Rules of Procedure granted the ABC Experts broad procedural discretion and investigatory powers, including the power independently to conduct such research as they deemed appropriate, without imposing any prohibitions against interviews with third parties such as Mr. Millington.149 In fact, there are other third parties who assisted the ABC Experts and who are acknowledged at the beginning of the ABC Experts' Report, but their participation was not objected to by the GoS in any way.150
157.
Further, even if one assumed that the Millington e-mail was inconsistent with the Parties' procedural agreements, the SPLM/A argues that this breach was not a serious violation of a fundamental procedural guarantee. Any such violation would at most have been an inadvertent misunderstanding of the limits of the ABC Experts' investigative authority, no different in character than contacts with other third parties against which the GoS has not protested.151 In any event, the SPLM/A believes that the GoS does not identify any procedural injury arising from the Millington e-mail, much less the sort of grave prejudice required to set aside an adjudicative decision. The Millington e-mail, in SPLM/A's view, was a single communication, barely a line long, which, at most, did nothing but conform to the interpretation that the ABC Experts had previously reached.152

(d) The ABC Experts Allegedly Failed to Act through the Commission, and to Seek Consensus, in Reaching Their Decision.

(i) GoS Arguments

158.
The GoS claims that Section 14 of the Rules of Procedure153 was violated when the ABC Experts did not endeavor to reach a decision by consensus. Instead, the ABC Experts purportedly made no attempt to reach a consensus among the members of the ABC as a whole.154 While the ABC Experts were to prepare the ABC Experts' Report and had the "final say," the ABC Experts' Report was to be the report of the entire Commission and not just the ABC Experts.155 In the GoS's view, the proper procedure set out in the Parties' procedural agreements was first to submit the (draft) Report to the ABC, after which the ABC as a whole would present the Report to the Presidency.
159.
Further, the GoS argues that is was neither informed nor consulted on the final outcome of the ABC Experts' Report despite the clear language and intent of the Abyei Protocol and the Rules of Procedure. No meeting was ever called to try to reconcile the views of the Parties. By excluding other ABC members from the decision-making process and by presenting the ABC Experts' Report to the Presidency without any consultation, the GoS asserts that the ABC Experts changed the very spirit of the special mechanism of dispute resolution that the ABC was supposed to embody.156 The GoS also emphasizes that it had consistently expressed its objection to this way of proceeding; in fact, following the presentation of the Report to the Presidency, the head of the GoS delegation immediately made clear its protest against the manifest violation of the ABC's mandate by the ABC Experts. Hence, the GoS argues that no waiver can be implied from their conduct.157
160.
In response to the SPLM/A's allegations that the GoS itself thwarted attempts at achieving a consensus by not agreeing to compromise during the ABC proceedings, the GoS contends such refusal to "compromise" did not entail a principled objection to achieving a "consensus," to which it was not opposed. According to the GoS, refusing a negotiated political "compromise" is clearly different from achieving a "consensus" on reasonable scientific findings.158

(ii) SPLM/A Arguments

161.
The SPLM/A maintains that the Parties' procedural agreements specifically provided that the ABC Experts were to prepare the final ABC Experts' Report, without restricting the ABC Experts' discretion as to when and how they might seek to achieve consensus. In its view, Section 14 of the Rules of Procedure merely contemplates that the ABC Experts shall make reasonable efforts to that effect ("will endeavor"), and does not prescribe any particular mandatory procedural steps. The SPLM/A claims that the Rules of Procedure left no room, as a practical matter, for the various procedural steps that the GoS suggests should have occurred.159
162.
The SPLM/A also maintains that the Parties repeatedly discussed the presentation of the ABC Experts' Report to the Presidency during the weeks before that presentation occurred. Throughout those discussions, the GoS purportedly did not object or state that the course being adopted by the ABC Experts was improper (or that the GoS preferred a different approach). On the contrary, the SPLM/A argues that the GoS made it clear that it expected no further efforts to achieve a consensus and that such efforts would have been futile.160 Thus, the SPLM/A believes that the GoS waived any possible objection to the ABC Experts' approach towards achieving consensus and manner of presenting the final ABC Experts' Report to the Presidency, as it had not raised any objections at any point when it could have done so.161 Moreover, the SPLM/A argues that any distinction made by the GoS between "compromise" and "consensus" is "empty and desperate" semantics.162
163.
Assuming however that the ABC Experts' efforts to achieve a consensus (or any lack of such efforts) was inconsistent with the Parties' procedural agreements, any failure was not, in the SPLM/A's view, a "serious violation of a fundamental procedural guarantee" that would allow the ABC Experts' Report to be set aside. In its reading of Section 14 of the Rules of Procedure, only reasonable efforts by the ABC Experts to achieve consensus were contemplated; further, the requirement in Section 14 to endeavor to reach consensus was prescribed by the ABC Experts themselves. Any violation of such a provision would thus at most be an inadvertent misunderstanding of the ABC Experts' own Rules of Procedure.163

3. Substantive Excess of Mandate Arguments

(a) Introduction

(i) GoS Argument

164.
Broadly, the GoS submits that the ABC Experts misinterpreted and misapplied their mandate by (i) using manifestly inadmissible justifications,164 (ii) deciding ultra petita, and (iii) deciding infra petita.165
165.
Specifically, the GoS argues that an excess of mandate under Article 2(a) of the Arbitration Agreement166 occurred when the ABC Experts acted ultra petita, by deciding on matters outside the scope of the dispute submitted by the Parties.167 The ABC Experts were also said to have substantively exceeded their mandate when they decided infra petita, by not answering the questions asked to it by the Parties.168 The GoS claims that the ABC Experts decided ultra petita by purporting to confer rights on the Ngok Dinka outside the Abyei Area and by limiting the Misseriya's traditional rights,169 and they decided infra petita by: (i) refusing to decide the question asked, (ii) answering a different question than that asked, and (iii) ignoring the stipulated date of 1905.170

(ii) SPLM/A Arguments

166.
The SPLM/A does not agree with the GoS's claims that the ABC Experts acted ultra petita by purporting to confer rights on the Ngok Dinka outside the Abyei Area and by limiting the Misseriya's traditional rights. It asserts that the GoS's claim that the ABC Experts acted outside their mandate rests on implausible and distorted readings of the ABC Experts' Report; the SPLM/A claims that the ABC Experts were merely making explicit that they had delimited the Abyei Area's territorial boundaries without purporting to affect the retained rights of usage of the Ngok or the Messiriya.171 Further, assuming arguendo that the ABC Experts did indeed confer or limit such rights, they still would not have exceeded their mandate.172
167.
The SPLM/A further asserts that the grounds put forward by the GoS to support its infra petita claims are in truth substantive disagreements with the ABC Experts' interpretation of the Abyei Area definition in Section 1.1.2 of the Abyei Protocol173. As such, these are not grounds for challenging the ABC Experts' Report as an excess of mandate.174 While consistently asserting that the ABC Experts' interpretation of the Abyei Area is correct, the SPLM/A contends that errors of law or interpretation do not give rise to an excess of mandate,175 nor are factual and evidentiary disagreements with the ABC Experts' conclusions valid grounds for claiming an excess of mandate.176 The SPLM/A also submits that the ABC Experts' interpretation of their mandate is entitled to a substantial presumption of correctness and accordingly could only be invalidated in a rare and exceptional case.177 Moreover, even assuming that the ABC Experts incorrectly interpreted their definition of the Abyei Area, the SPLM/A argues that an excess of mandate can only be sustained where the adjudicatory authority purported to act beyond its authority in a glaring, manifest, or flagrant manner.178

(b) The ABC Experts Allegedly Refused to Decide the Question Asked

(i) GoS Arguments

168.
The premise of this GoS argument is its rejection of the ABC Experts' interpretation of the Formula: instead of interpreting the definition of the Abyei Area as referring to the area of the nine Ngok Dinka chieftains transferred to Kordofan in 1905 (which it calls the "territorial interpretation"), the GoS believes that the ABC Experts interpreted the Formula as referring only to the area the nine Ngok Dinka chieftains used and occupied in 1905 (which it calls the "tribal interpretation").179
169.
The GoS contends that the mandate of the ABC Experts was clear, i.e., to define an area transferred in 1905. However, the ABC Experts, according to the GoS, allegedly declined to answer the question they were charged with answering.180 Instead, they "sought to determine as accurately as possible the area of the nine Ngok Dinka Chiefdoms as it was in 1905."181 By deviating from the question of defining "the area of the nine Ngok Dinka Chiefdoms transferred to Kordofan in 1905" to that of "the area of the nine Ngok Dinka Chiefdoms as it was in 1905" - the transfer being left aside - the ABC Experts allegedly decided in excess of their mandate. Put differently, the ABC was tasked to find the "lines" constituting the boundary of the area transferred to Kordofan in 1905, and not to define the territory that the Ngok Dinka used and occupied in 1905.182 The GoS submits that the question of an area transferred at a given date is different from that of an area occupied by particular peoples or chiefdoms at the same date. The ABC Experts thus effectively substituted their question for that agreed and asked by the Parties.183

(ii) SPLM/A Arguments

170.
In the SPLM/A's view, the ABC Experts clearly defined and demarcated the Abyei Area, doing so both with specific latitudinal and longitudinal coordinates, and by delimiting the same coordinates on Map 1 of the ABC Experts' Report, thus showing the Abyei Area boundaries. The SPLM/A asserts that this was precisely the task that the ABC Experts were mandated to perform.184 Moreover, the SPLM/A submits that the definition of the Abyei Area as interpreted by the ABC Experts, (i.e., by reference to the entire historic territory of the Ngok Dinka people in 1905), was consistent with the ABC Experts' explanations during the ABC's proceedings which had been received without objection by the Parties.185 It further asserts that the ABC Experts' interpretation of the Abyei Area is the natural, grammatically correct meaning.186
171.
The SPLM/A repeatedly states that the ABC Experts' interpretation of the Abyei Area definition was a matter of substantive interpretation of the Abyei Protocol, which cannot form the basis of an excess of mandate claim.187 It submits that the real complaint of the GoS is with the substance of the answer, rather than a failure to provide an answer.188

(c) The ABC Experts Allegedly Answered a Different Question Than That Asked

(i) GoS Arguments

172.
Instead of determining "the area of the nine Ngok Dinka Chiefdoms transferred to Kordofan in 1905" (which the GoS posits to be a question of fact), the GoS submits that the ABC Experts reformulated the question in terms of dominant and secondary rights by the Ngok Dinka and the Misseriya over the territory.189 For this reason, the GoS criticizes the ABC Experts' consideration of "territorial occupation and/or use rights" and "population dynamics" in determining the Abyei Area.190
173.
In the GoS's view, it was not necessary to determine the nature of the established land or territorial occupation and/or use rights by all nine Ngok Dinka chiefdoms in order to delimit and demarcate the boundaries of the transferred area.191 The ABC Experts had at their disposal official documents that would have allowed them to determine the transferred area, but they allegedly set these aside in favor of the disputed methodology.192
174.
Further, even assuming that the ABC Experts were entitled to consider land use rights, the failure of the ABC Experts to consider the land use rights of any of the Humr omodiyas is for the GoS an indication of the partisan nature of their inquiry.193

(ii) SPLM/A Arguments

175.
For the SPLM/A, this line of argumentation is simply the converse or mirror image of the previous argument that the ABC Experts refused to answer the question that was addressed to them.194 It reiterates that the argument does not actually point to an excess of mandate, but rather to a substantive disagreement with the ABC Experts' reasoning and factual appreciation of the evidence.195
176.
In the SPLM/A's view, the ABC Experts could hardly determine what the boundaries of the Abyei Area were without determining what was included in the 'area of the nine Ngok Dinka Chiefdoms.'196 Thus, in order for them to determine the boundaries of the Ngok Dinka that were transferred for administrative reasons in 1905, they needed to determine the nature of the established land or territorial occupation and/or use rights by all the nine Ngok Dinka chiefdoms.197
177.
The SPLM/A also contests the assertion that the ABC Experts did not consider "any of the Humr omodiyas,"198 arguing that the ABC Experts considered "with great care and diligence the land use of the Misseriya."199

(d) The ABC Experts Allegedly Ignored the Stipulated Date of 1905

(i) GoS Arguments

178.
The GoS maintains that the ABC Experts virtually ignored the agreed date for determining the transferred area (i.e., 1905). In particular, they allegedly did not provide any information as to the position of tribes in 1905 which would warrant a line anywhere north of the Bahr el Arab, still less one as far north as latitude 10°22'30"N. Instead, they purportedly made reference to other wholly irrelevant dates, ignoring that their mandate was restricted to determining what area was transferred in 1905.200 The GoS points out that despite repeated references to "1905" in the ABC Experts' Report, the critical date does not appear once in the "Final and Binding Decision."201
179.
The GoS takes specific exception to the ABC Experts' reliance on the 1965 Peace Agreement between the Messiriya Humr and the Ngok Dinka.202 The GoS notes that the 1965 agreement was superseded by the Abyei Agreement of 1966, and that the ABC Experts were not empowered to refer to the 1966 agreement at all "except as [it] may have shed light on the position in 1905." The GoS contends that the 1966 Agreement does not do this.203 Further, the GoS claims that the 1965 agreement was only used to provide absolute evidence of "the continuity of Ngok Dinka settlements in, and use of, places north of the Bahr el-Arab between 1905 and 1965" which, even if it were true, would still not be relevant to the question which the ABC Experts were mandated to answer.204

(ii) SPLM/A Arguments

180.
According to the SPLM/A, the ABC Experts' Report makes perfectly clear that the ABC Experts in no way ignored the 1905 date; instead, they based their determination of the Abyei Area's boundaries precisely on their assessment of the extent of the area of the nine Ngok Dinka Chiefdoms in 1905.205 Counting 48 separate references to the 1905 date in the 45-page ABC Experts' Report, it asserts that "[i]t is impossible to read the ABC Experts' Report and conclude that the ABC Experts somehow 'ignored' or 'virtually ignored' the 1905 date."206
181.
In the SPLM/A's view, there were evidentiary difficulties in determining the extent of the Ngok Dinka territory in 1905. It was thus necessary for the ABC Experts to avail themselves of materials produced both before and after 1905, as well as during that year. The materials from earlier and later periods were considered only to determine circumstantially and indirectly what the territory of the Ngok Dinka had been in 1905.207
182.
The SPLM/A also notes that the GoS itself cited and relied on events occurring after 1905 as evidence of the location of the Ngok Dinka and Misseriya in 1905,208 and that the GoS used these in its presentations before the ABC as well.209

(e) The ABC Experts Allegedly Allocated Grazing Rights

(i) GoS Arguments

183.
The GoS submits that the ABC Experts exceeded their mandate by purporting to allocate secondary grazing rights to the Ngok Dinka and the Misseriya. In the GoS's view, the ABC's mandate was strictly limited to drawing the line constituting the border of the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905, and this task cannot be interpreted as encompassing any findings regarding allocation or limitation of grazing rights.210 By making a pronouncement regarding grazing or other secondary rights, the decision clearly exceeded the ABC Experts' mandate.211
184.
The GoS asserts that the recognition of such secondary rights is a clear "decision" on the part of the ABC Experts, and could not have been a mere "rationale" for the ABC Experts' boundary delimitation. The GoS contends that if the allocation had been mere rationale, it would not have been included in the "Final and Binding Decision" featured at the end of the Report.212 Moreover, even if the allocation were mere rationale, it would confirm that the ABC Experts' decision was based not on the territorial transfer that occurred in 1905, but on the "arbitrary or equitable division of tribal rights."213
185.
The GoS rejects the argument that the allocation was a justifiable exercise of incidental or ancillary authority derived from the ABC Experts' primary mandate.214 It asserts that while "the purpose of incidental or ancillary powers is to provide for the full and orderly settlement of disputes submitted by the parties," the allocation of secondary rights was not part of the dispute submitted to the ABC, and a pronouncement on this matter was not necessary to provide for the "orderly settlement of all matters in dispute."215
186.
The GoS also argues that this pronouncement cannot simply be brushed aside as an unintentional or minor excess that does not affect the remainder of the Report. As an alleged excess of mandate, the allocation supposedly triggers the operation of Article 2(c) of the Arbitration Agreement.216
187.
In addition, the GoS argues that the ABC Experts exceeded the geographical scope of their mandate by conferring on the Ngok secondary rights to land outside the Abyei Area and by limiting the Misseriya's traditional grazing rights to the southern part of the shared area.217 The GoS submits that there is no trace in the applicable instruments - whether the Abyei Protocol, the Abyei Appendix or the Terms of Reference of the ABC - of any mandate given to the Commission or to its ABC Experts to ascertain, attribute, regulate or share grazing rights on both sides of the alleged boundary.218

(ii) SPLM/A Arguments

188.
In response, the SPLM/A contends that the ABC Experts did not commit an excess of mandate by purporting to confer rights on the Ngok Dinka outside the Abyei Area.219 For the SPLM/A, the ABC Experts' Report merely set forth in summary form the ABC Experts' historical conclusions, which in turn provided the rationale for their subsequent boundary delimitation. The SPLM/A believes that the ABC Experts simply sought to make clear, for the avoidance of any doubt, that their decision only defined the Abyei Area's territorial boundaries and did not affect other pre-existing rights which either the Ngok or the Messiriya already possessed and retained.220 The SPLM/A claims that the ABC Experts, during their public meetings, encountered popular misconceptions about the effect that setting a boundary would have. This supposedly led the ABC Experts to emphasize the limited scope of their territorial decision in order to assuage popular misconceptions about traditional rights.221
189.
In the alternative, the SPLM/A argues that even if there were some ambiguity as to the meaning of the ABC Experts' Report or in its treatment of the issue of grazing rights, the ABC Experts' statements regarding the Ngok Dinka's retention of their rights are to be interpreted consistently with the ABC Experts' mandate, and not as overstepping that mandate. Accordingly, if there is some doubt, the ABC Experts' decision should be read in a manner that does not purport to alter or affect the rights of the Ngok Dinka or Misseriya outside the boundaries of the Abyei Area.222 Also, even if the ABC Experts were considered to have attempted to confer rights on the Ngok Dinka outside Abyei Area proper, the SPLM/A submits that this would merely be a valid "exercise of incidental or ancillary authority, which was included in the ABC Experts' primary mandate."223
190.
The SPLM/A also maintains that an excess of mandate only exists where the adjudicatory authority purported to act beyond its authority in a glaring, manifest or flagrant manner.224 It submits that any findings by the ABC Experts in relation to Ngok Dinka grazing rights would not have been such an egregious excess of mandate, and that the rights would have affected "only a very specific and limited right of usage" due to the seasonal conditions there.225
191.
Finally, even assuming the ABC Experts did exceed their mandate by purporting to confer grazing rights they were not permitted to grant, the SPLM/A contends that this portion of the Report would be severable from the remainder of the ABC Experts' Report.226

4. Violation of Mandatory Criteria in carrying out the Mandate

(a) Introduction

192.
In its Memorial, the GoS submits that as a general principle of law, the failure of a panel charged with deciding a dispute to state any reasons on the basis of which its decision can be supported, constitutes an excess of mandate.227 It identified four acts by the ABC Experts which allegedly violated "mandatory criteria" in carrying out their mandate: (i) failure to give reasons; (ii) rendering a decision based on "equitable division" or taken ex aequo et bono, (iii) applying unspecified "legal principles in determining land rights," and (iv) attempting to allocate oil resources under the guise of the transferred area.
193.
In its Counter-Memorial, the SPLM/A responds that none of the violations of supposed "mandatory criteria" alleged by the GoS fall within the definition of an excess of mandate. It argues that the GoS derives its "mandatory criteria" from sources external to the Parties' agreements,228 including the ICSID Convention, UNCITRAL Model Law, and various institutional arbitration rules.229
194.
In its later pleadings, the GoS merged its discussion of the four alleged violations with its substantive excess of mandate arguments, arguing that the ABC Experts decided ultra petita.230 The SPLM/A continues to assert that there is nothing in the Parties' agreements forbidding the four alleged violations; as such, there is, in its view, no conceivable way to characterize these as "ultra petita" of what was agreed between the Parties.231

(b) The ABC Experts Allegedly Failed to Provide Reasons Capable of Forming the Basis of a Valid Decision

(i) GoS Arguments

195.
For the GoS, it is a general principle in modern systems of law that an adjudicative decision be motivated (that is, supported by reasons). In its view, a decision can be provided without disclosing the reasons behind it only when the parties to a dispute have expressly waived this requirement.232 Thus, the GoS does not request that the Tribunal determine whether the ABC Experts were right or wrong, but only whether they had given any reasons in support of their decision.233
196.
The GoS cites decisions by the ABC Experts that purportedly lacked justification: (a) the rejection of the Bahr el Arab as the southern boundary of Kordofan; (b) the assertion that latitude 10°10'N constitutes the southern boundary of Misseriya rights/northern boundary of Ngok rights;234 and (c), following from (b), the assertion that latitude 10°35'N constitutes the northern boundary of Ngok Dinka rights.235 The GoS asserts that these were three absolutely crucial decisions of the ABC Experts that were unsupported by reasoning.236
197.
With respect to decision (a) above, the GoS notes the ABC Experts found that the "Ragaba ez-Zarga/Ngol, rather than the river Kir, which is now that Bahr el-Arab, was treated as the province boundary [between the provinces of Kordofan and Bahr el Ghazal], and that the Ngok people were regarded as part of the Bahr el Ghazal Province until their transfer in 1905."237 The GoS argues that assuming arguendo this is true (it later argues that it is not), the transferred area should have been south of the Ragaba ez Zarga. Instead, the GoS alleges, the ABC Experts fixed the northern boundary of the Abyei area further north (and not south) of the Ragaba ez Zarga without providing any reason.238
198.
With respect to decision (b) above, the GoS observes that the ABC Experts fixed "Ngok claims to permanent rights southwards roughly from 10°10'N [latitude] and of Ngok secondary rights extending north of that line."239 However, while this latitude is mentioned several times in the ABC Experts' Report, the GoS contends there is nothing in the Report explaining how this latitude was arrived at and why Ngok Dinka dominant rights were fixed here.240
199.
With respect to decision (c) above, the GoS notes that the ABC Experts fixed the 10°35'N latitude as the northern limit of the Misseriya rights. Again, the GoS argues that other than noting that the line corresponds more or less with Dinka names on certain maps, there is no justification as to how this latitude was fixed.241

(ii) SPLM/A Arguments

200.
In response, the SPLM/A submits that the GoS arguments ignore the following: (i) nothing in the Parties' agreements or applicable law required the ABC Experts to give reasons;242 (ii) even where reasons are required, international and national arbitration instruments permit arbitral awards to be invalidated only in rare and exceptional cases;243 (iii) the ABC Experts' Report provided extensive, well-considered, and erudite analysis which fully satisfy any conceivable requirement for reasons;244 (iv) the GoS's two "illustrations" of inadequate reasoning are misconceived and irrelevant;245 and (v) the GoS's complaints about the ABC Experts' reasons are nothing more than objections to the substance of the ABC Experts' Report.246
201.
For decision (a), the SPLM/A argues that: for the ABC Experts, the decisive issue was determining the territory of the nine Ngok Dinka chiefdoms as they stood in 1905, and not the location of the putative provincial boundary. They thus defined the Abyei Area as "the area of the nine Ngok Dinka chiefdoms as it was in 1905," and the location of the Kordofan/Bahr el Ghazal boundary (whether at the Bahr el Arab or the Ragaba ez Zarga) was not determinative of the question of the territory of the nine Ngok Dinka chiefdoms.247
202.
For decisions (b) and (c), the SPLM/A argues that the ABC Experts found evidence showing that Ngok villages were located widely throughout the Bahr river basin, extending up to the southern boundary of the goz at 10°10'N. The GoS claim that there is no reference to this latitude (other than as a decision) is said to ignore the fact that the ABC Experts' Report expressly equates latitude 10°10'N with the southern boundary of the goz, while the northern boundary was found to be at 10°35'N. The ABC Experts' Report accepted the existence of both Ngok and Misseriya secondary rights to the area between 10°10'N and 10°35'N and explained why the character of the goz, not being occupied by either tribe, made it an appropriate boundary strip. Reasoning that this gave the Parties' equal secondary rights in the goz, the ABC Experts found it appropriate to divide that area equally between the Parties with the boundary drawn at 10°22'30"N.248

(c) The ABC Experts Allegedly Decided Based On "Equitable Division"/Taken Ex Aequo Et Bono

(i) GoS Arguments

203.
The ABC Experts found that in the goz (the area between the latitudes 10°10'N and 10°35'N) the Misseriya and the Ngok Dinka communities exercised equal secondary rights to use of the land on a seasonal basis. They concluded that "[t]he two Parties lay equal claim to the shared areas and accordingly it is reasonable and equitable to divide the Goz between them,"249 and bisected equally the band between latitudes 10°10'N and 10°35'N at latitude 10°22'30"N. The GoS submits that the ABC Experts completely disregarded and thereby exceeded their mandate by dividing the goz on an "equitable" basis in this way.250 It claims that the ABC Experts were not mandated to establish shared areas and, moreover, they were not mandated to divide the shared area by way of a decision taken ex aequo et bono.251 Because of this determination (and in particular, the choice of the 10°22'30"N latitude), the GoS argues that the conclusion of the ABC Experts on the delimitation of the Abyei Area is illegitimately based on pure equity.252 The GoS asserts that an adjudicative body can only decide ex aequo et bono when it is expressly authorized to do so, and this requirement is particularly cogent when a sovereign state is involved.253
204.
The GoS also refutes the allegation that the ABC Experts acted upon the "legal principle of the equitable division of shared secondary rights," as this legal principle does not appear to exist.254 Further, should such a principle exist, the GoS contends that the ABC Experts were instructed to decide based on "scientific analysis and research," which excludes reliance on the alleged legal principle.255

(ii) SPLM/A Arguments

205.
The SPLM/A rejects the argument that the ABC Experts decided ex aequo et bono. According to the SPLM/A, where two parties enjoy "equal" rights to the same territory, it is not a decision ex aequo et bono to divide the territory "equally" between them. Rather, it is said to simply be a decision made on the basis of the two parties' respective, and equal, historical use of and rights to the same territory.256
206.
The SPLM/A emphasizes that the ABC Experts relied on "the legal principle of the equitable division of shared secondary rights" in mandating this equal division. Thus, even if they erred in their understanding or application of those legal principles, the SPLM/A argues that the ABC Experts plainly did not render a decision ex aequo et bono. Instead, they applied what they took to be the law to a very carefully defined circumstance of shared and equal secondary rights in a specific territory.257
207.
In the alternative, the SPLM/A asserts that even if the decision was based on principles of equity, it would not amount to a decision ex aequo et bono. For the SPLM/A, equity is a general principle of law, distinguishable from a decision ex aequo et bono, which may properly be applied by an international tribunal even without express or specific consent by the Parties.258 Further, even assuming that the decision was taken ex aequo et bono, it argues that there is nothing in the Parties' agreements or in any general principles of law that forbids a decision ex aequo et bono.259 Nor is there a need for the Parties to consent before a decision ex aequo et bono can be made.260

(d) The ABC Experts Allegedly Applied Unspecified Legal Principles In Determining Land Rights

(i) GoS Arguments

208.
In dividing the goz between the latitudes 10°10'N and 10°35'N," the ABC Experts based their decision on the "legal principle of the equitable division of shared secondary rights."261 The GoS alleges that despite such reliance, the ABC Experts failed to identify with precision what this principle was or where it came from.262
209.
Moreover, the GoS submits, the ABC Experts were supposed to base their decision on "scientific analysis and research," and not on legal principles for determining land rights in former British-administered African territories, as they purported to have done.263

(ii) SPLM/A Arguments

210.
Preliminarily, according to the SPLM/A, the GoS makes no effort to reconcile its claim that the ABC Experts rendered their decision ex aequo et bono with its complaint that the ABC Experts' decision wrongly relied on legal principles; nor does the GoS cite any legal authority that might establish the mandatory principles on which it relies.264 In the SPLM/A's view, there was nothing in the Parties' agreements that forbade the ABC Experts from considering legal principles - indeed, the logical predicate for the GoS ex aequo et bono argument is that the ABC Experts were required to consider legal principles. Moreover, nothing in the Parties' agreements required the ABC Experts to specify the source of the legal principles they applied or to write a lengthy description of what those alleged legal principles were.265
211.
In any event, the SPLM/A submits that the ABC Experts identified the legal principles that they referred to as applicable in "former British colonies and protectorates, including Sudan (a Condominium)" and "Sudan" at the "time of the Condominium" and moreover cited a number of secondary sources about Sudanese and British colonial law. For the SPLM/A, the GoS's objections to the accuracy of the legal analysis is not relevant to the excess of mandate question, while its objections to supposedly undefined legal principles are unfounded because the terms of the ABC Experts' Report identified the sources of the legal principles the ABC Experts relied upon.266

(e) The ABC Experts Allegedly Took into Account the Location of Oil Fields in Deciding on the Transferred Area

(i) GoS Arguments

212.
The GoS observes that the northern boundary determined by the ABC Experts makes a perfect straight line, and the eastern boundary runs southwards in a perfect 90° angle to that northern boundary. As a consequence, all the major oilfields of Sudan are "conveniently" included in the Abyei Area.267 The GoS alleges that the ABC Experts took into full consideration the "Wealth Sharing" provisions in the CPA and Section 3 of the Abyei Protocol, which they strictly had no competence to take into account.268 According to the GoS, this constituted an obvious excess of mandate.269 The GoS also claims that, as admitted by the SPLM/A, the eastern boundary of the Abyei Area was "created" by the 90° southern turn, and the "created" eastern boundary was an excess of the ABC Experts' mandate, which was merely to define the boundary resulting from an executed transfer.270
213.
The GoS also argues that evidence of partiality on the part of the ABC Experts is found in an interview given by Dr. Douglas Johnson, one of the ABC Experts, to the Sudan Tribune on May 29, 2006,271 as well as in the fact that Dr. Johnson was later engaged as an expert consultant by the Government of South Sudan.272 The ABC Experts allegedly knew about the location of the oil fields in Abyei at the time they wrote the report, as such information was already available in 2005.273 Because of such purported lack of impartiality, the GoS argues that its fundamental right to equal and impartial treatment was violated.274 Further, such considerations are also allegedly indicative of the fact that the ABC Experts did not decide on the basis of "scientific analysis and research."275

(ii) SPLM/A Arguments

214.
For the SPLM/A, the ABC Experts' Report explains in detail the reason for the choice of borders, and the suggestion that the north-east turning point was motivated by partiality cannot be sustained.276 While the ABC Experts accepted the specific co-ordinates of the eastern boundary proposed by the SPLM/A,277 the SPLM/A notes that these co-ordinates were not challenged by the GoS, which offered no evidence and made no claims regarding where the eastern boundary of the Abyei Area should lie if the ABC Experts concluded that the northern boundary was above the River Kir.278
215.
The SPLM/A also attempts to show how, in its view, the ABC Experts selected the eastern boundary (and the north eastern turning point): as a result of the Abyei Protocol, the southern and western boundaries of the Abyei Area were expected to follow existing boundaries, and only the northern and eastern boundaries remained to be identified, defined and demarcated by the ABC. After determining the northern boundary at approximately the 10°22'30"N latitude, the ABC Experts were purportedly faced with the situation in which no natural "cut-off line" existed to create an eastern boundary, as this latitude continues uninterrupted by other internal boundaries all the way to the Kordofan-Upper Nile boundary (approximately 260 kilometers further east than the point at which the north-east corner of the boundary as determined by the ABC Experts lies). According to the SPLM/A, the ABC Experts had little alternative but to draw a "dog-leg" extending south from the northern boundary to some appropriate place in order to complete the Abyei Area. The "dog-leg" chosen extended the existing line of the Kordofan-Upper Nile boundary at 29°32'15"N longitude (where the boundary makes an approximate 60° turn east) due northwards to meet latitude 10°22'30"N (this appears as a perpendicular line). Further, the SPLM/A asserts that the ABC Experts had been presented with evidence that the Ngok Dinka were located in 1905 in areas very close to 29°32'15"N.279
216.
Finally, the SPLM/A submits that Dr. Johnson's interview could not be evidence that the ABC Experts acted partially. On the contrary, as he explained in the interview, the ABC Experts were not shown a map of where the oil wells were.280

5. Admissibility of Excess of Mandate Claims

217.
As a counter to the GoS's claims that the ABC Experts exceeded their mandate, the SPLM/A raises a number of claims of its own, contending that: (a) that the GoS excluded or waived any rights to claim that the ABC exceeded their mandate, and (b) the ABC Experts' Report is entitled to presumptive finality.

(a) The GoS Allegedly Waived its Objections to the ABC Experts' Report

(i) SPLM/A Arguments

218.
The SPLM/A submits that the GoS waived its objections to the ABC Experts' Report by agreeing that the Report would be final and binding and would be given immediate effect without any possibility for appeal or other challenge.281 The SPLM/A notes that this agreement was recorded specifically in the Abyei Appendix, the Abyei Protocol, the Terms of Reference and the Rules of Procedure; none of these instruments provides that the ABC Experts' Report would be subject to any sort of review or possible delay in implementation by either Party.282
219.
Furthermore, the SPLM/A believes it well-settled that jurisdictional and procedural objections must be raised at the earliest opportunity; otherwise they are waived. For the SPLM/A, the GoS raised no objections at any time during the ABC's work (instead, it actively participated); moreover, the GoS repeatedly and explicitly affirmed that the ABC's decision would be final and binding.283
220.
The SPLM/A also posits that it cannot be prevented (or estopped) from claiming that GoS waived its rights to claim an excess of mandate, as the choice of law clause in the Arbitration Agreement allowed the application of general principles of law and practice, such as the rules of waiver and exclusion, to govern this dispute.284

(ii) GoS Arguments

221.
In response, the GoS argues that it was precisely because there were serious doubts about respect for their mandate by the ABC Experts that both Parties agreed, pursuant to the Arbitration Agreement, to submit the present dispute to the Tribunal. Since it has agreed to these proceedings, it is the SPLM/A that is now estopped from raising objections against the jurisdiction of the Tribunal.285
222.
The GoS also asserts that it had fully and completely complied with the requirement that jurisdictional objections must be raised at the earliest opportunity. It immediately objected to the ABC Experts' Report when it was presented to the Presidency on the ground that the ABC Experts failed to respect their mandate. As for other procedural violations, the GoS claims that it protested as soon as such violations were brought to its knowledge.286 A waiver of rights by a State cannot be presumed lightly, and the GoS argues that it expressly and vigorously protested as soon as it came to know of violations of its rights.287

(b) The GoS is Allegedly Bound by the Principles of Presumptive Finality

(i) SPLM/A Arguments

223.
For the SPLM/A, the ABC conducted itself in the manner of an adjudicative body and rendered an adjudicative decision, leaving no doubt that the principles of finality and res judicata were applicable to the ABC Experts' Report.288 Moreover, the presumptive finality and validity of international adjudicatory decisions is especially compelling where boundary determinations are at issue.289 The principle of presumptive finality and validity means that an adjudicative decision or an award can be set aside solely in rare, narrow and exceptional circumstances,290 such as when the relevant parties agree.291 Here, SPLM/A submits that the Arbitration Agreement has not set aside the ABC Experts' Report and the principle of presumptive finality and validity still applies.292

(ii) GoS Arguments

224.
The GoS agrees that, in principle, boundary settlements enjoy a particular stability and permanence. However, the GoS maintains that the boundary has not been definitely settled in this case. According to it, the Tribunal has been charged by the Parties with determining whether there has been an excess of mandate, and, if the answer is in the affirmative, with defining the boundaries of the Abyei Area. It is only after the Tribunal has performed its duty that principles of res judicata and finality will apply.293

B. DELIMITATION OF THE ABYEI AREA

225.
If, as a result of its "excess of mandate" inquiry under Article 2(a) of the Arbitration Agreement, the Tribunal were to decide that the ABC Experts did exceed their mandate, then it would "proceed to define (i.e. delimit) on map the area of the nine Ngok Dinka Chiefdoms transferred to Kordofan in 1905" in accordance with Article 2(c) of the Arbitration Agreement. Within the ambit of Article 2(c) inquiry, the GoS submits that "the boundaries of the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905 are as shown on Figure 17 on page 159 of the GoS Memorial, being the area bounded on the north by the Bahr el-Arab and otherwise by the boundaries of Kordofan as at independence."294
226.
According to the GoS, the question of delimiting the Abyei Area must first be answered by determining what the provincial boundary between Bahr el Ghazal and Kordofan was before the 1905 transfer, as the transfer to Kordofan could not have included any areas previously located in Kordofan. Second, delimitation must include an identification of the area of the nine Ngok Dinka chiefdoms which previously fell within the province of Bahr el Ghazal and which was transferred to Kordofan in 1905.295
227.
By contrast, the SPLM/A submits that the putative boundary between Kordofan and Bahr el Ghazal, which it claims was indefinite and indeterminate, does not define the Abyei Area. In the SPLM/A's view, if the Tribunal were to decide that the ABC Experts exceeded their mandate, then it "should go on to define the Abyei Area to encompass all of the territory occupied and used by the Ngok Dinka in 1905"296 and declare that "the boundaries of the area of the nine Ngok Dinka Chiefdoms transferred to Kordofan in 1905 are the current boundary of Kordofan and Bahr el-Ghazal to the south extending to 10°35'N latitude to the north and the current boundary of Kordofan and Darfur to the west extending to 29°32''15'E longitude to the east."297

1. The scope of the Tribunal's mandate under Article 2(c) of the Arbitration Agreement

(a) GoS Arguments

228.
According to the GoS, if the Tribunal determines pursuant to Article 2(a) of the Arbitration Agreement that the ABC Experts exceeded their mandate, then it must, under Article 2(c), decide de novo and reach its own conclusion on the delimitation of the Abyei Area based on the Parties' submissions.298 The GoS insists that the triggering of Article 2(c) should occur once the Tribunal finds an excess of mandate "in any respect."299
229.
Accordingly, as to the probative value of the ABC Experts' Report under Article 2(c) inquiry, the GoS maintains that the Tribunal may take information contained in the Report into account, but only as mere evidence.300

(b) SPLM/A Arguments

230.
By contrast, the SPLM/A submits that in the event that elements of the ABC Experts' Report are found to be in excess of mandate, any portions of the ABC Experts' Report that are not so vitiated must, under general principles of law, remain final and binding on the Tribunal.301
231.
Moreover, the SPLM/A maintains that the Tribunal is not a de novo decision-maker under Article 2(c) of the Arbitration Agreement. Consequently, if the Tribunal were to hold that the ABC Experts exceeded their mandate under Article 2(a), then "it would be appropriate for the Tribunal to rely upon the Commission's determinations concerning the scope of the Abyei Area."302

2. The interpretation of the definition of the Abyei Area as set out in the Abyei Protocol and the Arbitration Agreement

232.
The GoS argues that the definition of the Abyei Area contained in Section 1.1.2 of the Abyei Protocol and Article 2(c) of the Arbitration Agreement should be interpreted as referring to the 1905 administrative transfer of a specific, territorially-defined area that previously formed part of the province of Bahr el Ghazal to the province of Kordofan (the "Territorial Interpretation").303 In contrast, the SPLM/A contends that these provisions should be understood as referring to the transfer of the Ngok Dinka people as a whole, i.e. not merely some of the nine Ngok Dinka Chiefdoms or some of their territory (the "TribalInterpretation").304 To support their respective positions, both Parties rely on (a) the plain language and grammatical meaning of the Formula, (b) the purposes underlying the definition chosen by the Parties, and (c) the drafting history of the Abyei Protocol.

(a) The plain language and grammatical interpretation of the Formula set out in Section 1.1.2 of the Abyei Protocol and Article 2(c) of the Arbitration Agreement

(i) GoS Arguments

233.
For the GoS, the plain meaning of the Formula is clear and does not require recourse to any supplementary sources of interpretation.305 The Formula has a temporal dimension: it refers to a "documented historical event" that took place in 1905,306 the "critical date [...] as of which the facts relating to the transfer fall to be assessed."307 It also has an obvious territorial dimension: it refers to "an area transferred at a defined time and not an area populated or used at some other, undefined time."308 The GoS thus contends that "the only reasonable and defensible interpretation of the text is that it mandates [this] Tribunal to 'confirm' on map the boundaries of the area of the [sic] transferred in 1905."309
234.
Examining the grammatical structure of the Formula, the GoS argues that in ordinary English, the word "transferred" is equally capable of qualifying the noun "area" as the phrase "nine Ngok Dinka chiefdoms."310 Read in context - a transfer between two provinces - the phrase "transferred to Kordofan" is in fact more likely to refer to "the area" rather than "the nine Ngok Dinka chiefdoms."311 The SPLM/A's application of a selfserving grammatical rule of proximity, instead of relying on euphony,312 is in the GoS's view utterly artificial.313 More importantly, the SPLM/A's interpretation allegedly ignores the preposition "to" after the verb "transferred." Even if the SPLM/A's grammatical construction were correct and "transferred" could only relate to "chiefdoms," the GoS maintains that the Formula could not possibly be interpreted as referring to all of the territory of the nine Ngok Dinka chiefdoms, including the territory of chiefdoms already in Kordofan in 1905.314
235.
In addition, the SPLM/A purportedly adds words that do not appear in the Formula when it argues that Section 1.1.2 of the Abyei Protocol "referred to all of the area of the nine Ngok Dinka Chiefdoms that were transferred in 1905"315 or "the area inhabited and used by the nine Ngok Dinka Chiefdoms."316 The words "all" and "that were" are ex post facto additions to the Formula that alter its plain meaning. For the GoS, the words "inhabited" and "used" introduce a demographic dimension otherwise absent from the Formula.317
236.
The GoS further submits that the SPLM/A misconstrues the language appearing in the 1905 transfer documents in order to corroborate its grammatical analysis and to conclude that all of the territory occupied and used by the Ngok Dinka was transferred to Kordofan in 1905.318
237.
Contrary to the SPLM/A's assertions, the GoS emphasizes that none of the relevant transfer documents refer to a transfer of the Ngok Dinka "people."319 Nor do they employ the words "inhabited and used" in referring to the transfer.320 Instead, they refer to "the country"321 or "the territories"322 of Sultan Rob, or the "districts"323 of Sultan Rob and Sheikh Rihan.324 The GoS relies in particular on Governor-General Wingate's statement that:

The districts of Sultan Rob and Okwai, to the south of the Bahr el-Arab and formerly a portion of the Bahr el-Ghazal Province, have been incorporated into Kordofan.325

238.
For the GoS, Wingate's Memorandum does not contain any reference to the Ngok Dinka "people" or the area "inhabited and used" by them, and clearly locates the "districts of Sultan Rob and Sheikh Rihan" "to the south of the Bahr el-Arab," purportedly the then provincial boundary, thus establishing a "specific geographic limitation to the districts that were transferred."326
239.
Finally, the GoS contends that the SPLM/A's own submissions before the ABC show that prior to adopting its new tribal reading of the Formula, the SPLM/A considered that the "area" or "territory" was the key criterion to the understanding of Section 1.1.2 and the 1905 transfer documents.327 Referring to the passage of the March 1905 SIR) concerning the transfer, the GoS points to the SPLM/A's argument before the ABC that

[…] the reasons for the transfer of the two areas and not the people are explicitly stated - the occasional raids by the Southern Kordofan Arabs.328

240.
The GoS concludes that the focus of the Formula in Section 1.1.2 of the Abyei Protocol is on the area transferred to Kordofan, not the people, as contended by the SPLM/A in its declarations before the ABC.329 In its view, this was also the focus of the Condominium officials in the 1905 transfer documents.330 The GoS thus submits that the Tribunal should conform to the terms of the Arbitration Agreement by giving full effect to the plain and ordinary language of the Formula,331 which refers to the transfer of a specific area.332

(ii) SPLM/A Arguments

241.
The SPLM/A's reading of the Formula differs. It argues that the phrase "the area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905" should be read in light of the "grammatical rule of proximity" whereby a "post-modifying construction in a noun phrase [relates] to the immediately previous noun."333 The SPLM/A contends that the grammatically correct reading of Section 1.1.2 is to relate the phrase 'transferred to Kordofan' to the noun of 'chiefdoms.'334 The latter, and not the "area," must be understood to have been transferred to Kordofan.
242.
For the SPLM/A, the use of the phrase "area" in turn "serves to describe quantitatively the nine Ngok Dinka Chiefdoms being transferred, indicating that the nine Ngok Dinka Chiefdoms are capable of being properly defined and demarcated."335 Otherwise, the draftsmen of the Abyei Protocol would have opted for the phrase "that part of the area... that was transferred."336 In addition, it is clear for the SPLM/A that Section 1.1.2 refers to all of the area in question, since the Formula includes the terms "nine Ngok Dinka chiefdoms."337 Submitting that three of the nine Ngok Dinka Chiefdoms are located entirely to the north of the Kir River,338 the SPLM/A argues that interpreting Section 1.1.2 in such a way as to exclude certain chiefdoms from the Abyei Area would contradict the plain language of the Section.339
243.
The SPLM/A goes on to argue that Section 1.1.2 refers to "a transfer of the Ngok Dinka from the administration of Bahr el-Ghazal to the administration of Kordofan."340 Therefore, contrary to the GoS's allegation, the SPLM/A's interpretation does take into account the phrase "transferred to Kordofan."341
244.
The SPLM/A also contends that its interpretation finds further support in the language of the 1905 transfer documents, which refer to a transfer of the Ngok Dinka Paramount Chief and/or his territories, not merely some sub-chief or some portion of his territories.342
245.
The 1905 Wingate Memorandum, which the GoS sees as a crucial document, merely describes the "general location of the Ngok and the Twic"343 in "an ex post facto and general summary of the earlier 1905 transfer decision (as he understood it)."344 Much more significant for the SPLM/A is the March 1905 SIR, whose plain language shows that the Condominium intended to transfer Sultan Rob, Sheikh Rihan and their people:345

It has been decided that Sultan Rob, whose country is on the Kir river, and Sheikh Rihan of Toj... are to belong to Kordofan Province. These people have, on certain occasions, complained of raids made on them by southern Kordofan Arabs, and it has therefore been considered advisable to place them under the same Governor as the Arabs of whose conduct they complain."346

246.
In the SPLM/A's view, the words "these people" obviously refer to the Ngok Dinka and the Twic people in their entirety, and not merely to two individuals (Sultan Rob and Sheikh Rihan).347 According to the ABC Experts, this document also provided "[…] the official principal reason for the transfer of the nine Ngok Dinka chiefdoms […]."348 It is the same document that the GoS clearly interpreted as registering a transfer of people when it referred before the ABC to "The Decision to Transfer the Ngok and Twij to Kordofan," and "The Reason [for] Transferring the Ngok and the Twij to Kordofan."349 The SPLM/A also notes that the GoS acknowledged in its Memorial that the transfer recorded in the March 1905 SIR was a transfer of "groups," "the Ngok and the Twic."350
247.
Lastly, the SPLM/A emphasizes the fact that during the ABC proceedings, the GoS never objected to the ABC Experts' unanimous interpretation of the definition of the Abyei Area, which reflects the natural meaning and purposes of Section 1.1.2. of the Abyei Protocol.351
248.
The SPLM/A thus concludes that the natural meaning and structure of the text in Section 1.1.2 of the Abyei Protocol can only be interpreted as referring to the transfer of the entire Ngok Dinka people.

(b) The purposes underlying the definition of the Abyei Area set out in Section 1.1.2 of the Abyei Protocol and Article 2(c) of the Arbitration Agreement

(i) GoS Arguments

249.
Having stated that "the context and object and purpose of the arbitration agreement provide the guideline for the interpretation,"352 the GoS focuses on the object and purpose of the 1905 transfer, which is also clear: "[i]t was an administrative decision to transfer an area from one province to another to enable better administrative control over tensions between Baggara Arab and Dinka tribes."353 The SPLM/A's reliance for its interpretation on other factors that are alien to the way the Condominium officials viewed the situation in 1905 is ill-founded.354
250.
Thus, the SPLM/A's argument that the GoS's reading of the Formula would arbitrarily divide the territory of the Ngok Dinka Chiefdoms is misplaced. The GoS insists that "[t]here was no intent by Sudanese Government officials at the time to 'arbitrarily divide' the Ngok Dinka."355 To the extent that there were any Ngok Dinka north of the Bahr el Arab, the provincial boundary in 1905, they were already in Kordofan and did not need to be transferred.356
251.
Similarly, the SPLM/A's complaint that the GoS's interpretation would exclude three of the nine Chiefdoms (the Alei, the Achaak and the Bongo) from the Abyei Area finds no support in the contemporary documents.357
252.
Further, the SPLM/A's contention that the GoS's interpretation would also exclude Abyei from the Abyei Area is at odds with both the contemporary evidence and the intention of the Anglo-Egyptian administrators at the time.358 The GoS points out that Abyei Town did not exist in 1905 and "played no role whatsoever in the thinking of Sudanese officials in 1905 when they decided the transfer […],"359 pointing further to Section 7 of the Abyei Appendix which contemplates that Abyei Town may not be located in the Abyei Area.360
253.
Lastly, the GoS dismisses as being "based on present day demographics" the SPLM/A's argument that the purpose of the Abyei Area's definition is to uphold the Ngok Dinka's right to self-determination, a concept that was not referred to in the Formula or taken into account in transferring the Ngok Dinka districts to Kordofan in 1905.361 Invoking the principle of self-determination now "is in effect to re-open the negotiated settlement of the Abyei Protocol for the benefit of one of the parties and to the detriment of the other."362
254.
In sum, "it is by reference to the events that took place in 1905 relating to the area that was transferred that the resolution of the present dispute should be based," not by reference to other factors irrelevant in 1905.363

(ii) SPLM/A Arguments

255.
The SPLM/A argues that its Tribal Interpretation of the Formula is in accordance with "the central purpose of the definition of the Abyei Area [which] was to specify that region whose residents would be entitled to participate in the Abyei Referendum."364 The Abyei Referendum being designed to permit the Ngok Dinka to vote on whether or not to be included in the South, the SPLM/A contends that it would be absurd to define the Abyei Area as including only some of the Ngok Dinka territory or some of the nine Chiefdoms.365 Such a definition would be contrary to the "basic principles of self-determination underlying the Abyei Protocol."366
256.
The SPLM/A maintains that, instead of addressing this issue, the GoS addresses the dissimilar question of the purpose of the 1905 transfer, which is "completely irrelevant to the purposes of the GoS and the SPLM/A in concluding the 2005 Abyei Protocol."367 The GoS's interpretation of Section 1.1.2 of the Abyei Protocol, which reduces the Abyei Area to a 14-mile wide strip of swamp land along the Bahr el Arab's southern bank, runs counter to the fundamental purpose of the Abyei Protocol and the CPA -- resulting in the exclusion of the majority of territory occupied and used by the nine Ngok Dinka Chiefdoms, including three chiefdoms in their entirety,368 and arbitrarily dividing Ngok Dinka lands on the basis of what was an uncertain, provisional and approximate boundary in 1905.369 Similarly, if the Abyei Area were to be limited to territory south of the Bahr el Arab/Kir, it would not be the "bridge" between the north and the south, as contemplated by Section 1.1.1 of the Abyei Protocol.370
257.
Further, the GoS's interpretation of the Formula excludes Abyei Town, which has been "the undisputed center of Ngok Dinka political, cultural and commercial life for more than a century," from the Abyei Area.371 The SPLM/A further argues that this inconceivable result would be incompatible with Section 7 of the Abyei Appendix. The GoS's argument that Abyei town did not exist in 1905 misses the point;372 it is a fact that the Ngok Dinka Paramount Chief resided in Burakol at the time, near present day Abyei Town.373
258.
The SPLM/A goes on to argue that the witness testimony of the individuals involved in the drafting of the Abyei Protocol (Lieutenant General Lazaro Sumbeiywo, Mr. Jeffrey Millington and Minister Deng Alor Kuol) confirms that the purpose behind the definition of the Abyei Area was to encompass the entirety of Ngok Dinka territory and all of the nine Chiefdoms.374
259.
Lastly, the SPLM/A stresses that the composition of the ABC, as contemplated in the Abyei Annex, included specialists "with complementary expertise precisely tailored to the task before them - defining the area used and occupied by the Ngok Dinka in 1905".375 In the same way, the Parties "provided a set of procedures that were equally well-tailored to the same task."376
260.
The SPLM/A concludes that "the obvious purposes of Section 1.1.2 and the other provisions of the Abyei Protocol and Abyei Appendix require defining the Abyei Area to include all of the territory of the nine Ngok Dinka Chiefdoms in 1905."377

(c) The drafting history of the Abyei Protocol

(i) GoS Arguments

261.
According to the GoS, the negotiating history of the Formula confirms that the 1905 transfer was not a transfer of people and thus supports the GoS's Territorial Interpretation.378
262.
During the 1999-2005 peace talks, Southern Sudan was granted the right to selfdetermination and, in January 2000, the SPLM/A requested that this right be exercised in a referendum that would include, inter alia, "the District of Abyei whose population is of Ngok Dinka."379 The GoS rejected the SPLM/A's request, arguing that Abyei was not part of the South380 and that the 1956 boundaries were "sacrosanct."381 The SPLM/A maintained that the boundary should be drawn further north to include "all the land allegedly inhabited by Ngok Dinka before the Abyei Agreement of 1966."382
263.
The GoS goes on to observe that it was the SPLM/A that introduced the concept of an area "annexed to the north for administrative purposes" for the first time in 2000.383 The GoS then notes that Dr. Douglas Johnson presented a paper at a workshop organized by IGAD in 2003 in which he explicitly referred to the passage of the March 1905 SIR concerning the transfer of Sultan Rob to the province of Kordofan.384 The GoS insists that "it was precisely this passage which led to the formulation of the ABC's mandate and that of the Tribunal […]."385 Indeed, on March 19, 2004, the US Special Envoy to Sudan, Senator Danforth, broke the deadlock with a proposal entitled "Principles of Agreement for Abyei" containing the agreed Formula.386 All attempts by the SPLM/A to qualify the Formula by reference to later dates so as to recuperate Ngok territorial gains subsequent to 1905 were rejected.387 The Formula was eventually enshrined in the Abyei Protocol388 and regarded as "self-explanatory" by the Parties.389
264.
The GoS concludes that the drafting history of the Formula warrants a Territorial Interpretation on at least three grounds:

1. The Abyei Protocol constituted an exception to the territorial principle of the uti possidetis of 1956, repeatedly affirmed in the CPA.

2. The territorial integrity of Kordofan was upheld against a claim to an extensive tribal boundary of 1966.

3. But an exception was made for an area administratively added to Kordofan in 1905. That area, once identified, could in principle be returned to Bahr el-Ghazal if the inhabitants preferred that course of action.390

(ii) SPLM/A Arguments

265.
The SPLM/A contends that its Tribal Interpretation of Section 1.1.2 of the Abyei Protocol is fully corroborated by the drafting history of the Abyei Protocol.391
266.
When the peace negotiations resumed between the Parties, the SPLM/A consistently emphasized in a number of papers that the Ngok Dinka had a right to self-determination392 and constituted a "single cultural unit," which "up to 1905 […] was administratively and politically a part of the South,"393 before its annexing to Kordofan.394 The GoS was for its part primarily concerned by the alleged Ngok Dinka northern expansion following 1905.395 It argued that the Abyei Area should only include the "traditional Abyei,"396 without putting forward an actual definition of the Area.397
267.
In its written submissions and at the hearings, the SPLM/A agreed however with the GoS that while the key passage from the March 1905 SIR - a document which clearly demonstrates that the 1905 transfer was the transfer of the Ngok Dinka people - was examined by the negotiators in 2003 and "led to the formulation of the ABC's mandate,"398 the Wingate Memorandum was not considered.399
268.
The SPLM/A goes on to note that, in March 2004, U.S. Senator Danforth presented to the Parties a U.S. proposal entitled "Principles on Agreement on Abyei," which defined Abyei as the "area of the nine Ngoc [sic] Dinka Chiefdoms transferred to Kordofan in 1905," thereby reproducing an important aspect of the SPLM/A's proposed formulation in its previous draft agreements.400 Further discussions eventually led to the production of a joint draft which mirrored the Danforth proposal and became Section 1.1.2 of the Abyei Protocol.401
269.
In the SPLM/A's analysis, it is clear that the final text was tailored to give effect to the unity of the Ngok Dinka people and its aspiration to self-determination,402 and not to truncate the Ngok Dinka traditional homeland by reference to the 1905 provincial boundaries of Sudan.403

3. The relevance of the Kordofan/Bahr el Ghazal boundary to the delimitation of the area transferred in 1905

(a) Did the Bahr el Arab constitute a precise and proclaimed provincial boundary between Kordofan and Bahr el Ghazal and the northern limit of the area transferred in 1905?

270.
The GoS argues that the Condominium administration was present in the Abyei region and explored it prior to and in 1905. Despite limited and short-lived uncertainty surrounding the location of the Bahr el Arab, it is clear that there was a precise boundary between Kordofan and Bahr el Ghazal on that river prior to the transfer and that the highest-ranking official, who knew where the Bahr el Arab was, considered it to be both the provincial boundary and the northern limit of the transferred area in 1905.404
271.
In contrast, the SPLM/A contends that, in 1905, at a time when there was virtually no administration in Southern Kordofan and Bahr el Ghazal, there was widespread and prolonged confusion as to the location of the Bahr el Arab. Contrary to the GoS's position, the provincial boundary between Kordofan and Bahr el Ghazal was indeterminate in 1905 and irrelevant to a transfer that concerned a people as opposed to a specific area.

(i) The state of Condominium knowledge and administration of the Abyei region in 1905

(x) GoS Arguments

272.
The GoS submits, relying on the writings of Francis Deng, that the remoteness of the Abyei region, and its inaccessibility to government officials in the early twentieth century, is greatly exaggerated.405 As indicated in the report of one of the GoS's experts for these proceedings, Mr. Alistair Macdonald, the early 20 th century was, on the contrary, a period of exploration designed to give the Condominium a better understanding of the Abyei area.406 Bayldon was expressly sent by Wingate407 to the region with the instructions to explore the Bahr el Arab, and his progress was monitored closely by Governmental officials.408 It is obvious that the authorities wanted to elucidate the "river situation."409 In opposition to the view of Professor Martin Daly, one of the SPLM/A's experts for these proceedings, that "British knowledge of the Ngok was based on a few hours' path crossing,"410 the GoS notes that between 1901 and 1904, Sultan Rob was visited at least once a year by British officials who even bestowed on him a Second Class Robe of Honor.411 Other important evidence of administration is the fact that the 1905 transfer itself was officially recorded in the Annual Reports for both the provinces of Kordofan and Bahr el Ghazal.412

(y) SPLM/A Arguments

273.
The SPLM/A submits that there was no effective administration of the regions of northern Bahr el Ghazal and southwestern Kordofan before the transfer in 1905.413
274.
In the early twentieth century, the region of southwestern Kordofan and northern Bahr el Ghazal was extremely remote and difficult to access, especially in the rainy season.414 Even in 1908, after the transfer, Condominium officials reported that the "whole Dinka country is difficult to traverse at any time."415 As stated by Professor Daly in his Report, the Sudan Government at that time was under-staffed and devoted most of its resources to more populous and accessible areas, such as Khartoum and the Nile Valley.416 The local tribes, including the Ngok Dinka, were under some form of self-governance, and "were in effect sovereign"417 and "left on their own."418 The British made no effort to effectively administer them.419 The officials did not establish any permanent post, schools or health clinics in the Abyei area.420 Their role was limited to "pacification" and maintaining order between the tribes.421 Therefore, "there was […] no point in delimiting a boundary"422 since "provincial boundaries simply did not matter."423 Even if some British officials were sent on expeditions in this area, the goal was not to explore or establish administrative control but to inform the local population that the British were now in charge of Sudan.424

(ii) The extent of the confusion regarding the location of the Bahr el Arab

(x) GoS Arguments

275.
The GoS acknowledges that Wilkinson, who traveled from El Obeid to Sultan Rob's in 1902, mistook the Ragaba ez Zarga for the Bahr el Arab.425 His mistake was reflected on the 1904 Sudan Intelligence Office Map426 and repeated by Percival.427
276.
The GoS further notes that the ABC Experts extensively relied upon Wilkinson's account to reject the Bahr el Arab as the northern boundary of Bahr el Ghazal428 and conclude that the Ragaba ez Zarga was treated as the provincial boundary in 1905.429 However, the GoS submits that the confusion was short-lived430 and ended before the transfer in February 1905 with Bayldon's report.431 The GoS cites to other contemporaneous reports432 and maps that Atlas); GoS Memorial, para. 319 referring to Walsh's report in the Sudan Intelligence Reports, No. 1605 (november 1907) Appendix B., p. 5 (SM Annex 15) and Sudan Intelligence Reports, No. 140, (March 1906), promptly corrected Wilkinson's mistakes and showed the Bahr el Arab at the right location.433 The GoS therefore agrees with Mr. Macdonald's conclusion that: "a true understanding of which river was the Bahr el-Arab had been reached in published form in 1907, although men such as Comyn had determined this a year or two earlier."434
277.
The GoS further insists that the very document on which the ABC Experts relied to demonstrate the confusion between the Ragaba ez Zarga and the Bahr el Arab, the 1905 Gleichen Handbook, contains a reference to Bayldon's correction of Wilkinson's mistake.435
278.
In addition, while much was known about the Bahr el Arab, the Ragaba ez Zarga was unknown both before and in 1905 and did not appear on a map before 1907.436 Given its indeterminate and seasonal nature, it could not have formed the boundary between Kordofan and Bahr el Ghazal up to the boundary with Darfur. Indeed, maps and travel accounts of the period all indicate that there was a tripoint on the Bahr el Arab between the provinces of Darfur, Bahr el Ghazal and Kordofan.437
279.
Finally, the GoS suggests that even if the ABC Experts were correct in determining that the Ragaba ez Zarga was the provincial boundary between Kordofan and Bahr el Ghazal before 1905, this would mean that the areas located north of the Ragaba ez Zarga were already part of Kordofan at the moment of the transfer, and as such could not have formed part of the area transferred. Therefore, the ABC erred in allocating areas to the Ngok Dinka that were north of the Ragaba ez Zarga.438

(y) SPLM/A Arguments

280.
The SPLM/A first points out that the Ragaba ez Zarga and the Bahr el Arab, which shared many of the same features and characteristics,439 were easily confused with each other.440 These similarities are confirmed by the historical record, and in particular the observations of Percival,441 Wilkinson442 and Lloyd443, Cunnison,444 witness evidence445 and modern expertise.446
281.
In addition, the SPLM/A argues that, contrary to the GoS's assertions, the confusion regarding the location of the Bahr el Arab was neither isolated, nor quickly resolved. Indeed, even though certain Condominium officials may have known where the real Bahr el Arab was, there was no general agreement as to its location.447 The confusion created by Wilkinson, who mistook the Ragaba ez Zarga for the Bahr el Arab,448 was shared by other officials such as Mahon,449 Percival,450 Boulnois,451 O'Connell,452 and Lloyd453 and reflected on maps, including the 1904 official Anglo-Egyptian Sudan Intelligence Office map reproduced in the 1905 Gleichen Handbook.454 It was also included in the 1906 Annual Report for Kordofan.455
282.
The SPLM/A further argues that the confusion was "in full force exactly at the time of the 1905 transfer of the Ngok Dinka."456 Contrary to the GoS's claim that Bayldon's correction of Wilkinson's mistake occurred in February 1905, the SPLM/A maintains that the documentary record clearly shows that the error "was not corrected until 1907 or 1908, two or three years after the 1905 transfer of the Ngok Dinka."457 The SPLM/A notes that the Bayldon report was not available in February 1905 as it was clearly dated 20 March 1905,458 and that Wingate's 1905 Memorandum indicates that "much of the course of these rivers is still unknown [...] and doubt still exists as to the correct names of the intricate waterways which intersect this part of the Sudan."459
283.
The SPLM/A thus argues that the conclusion of the ABC Experts as to when the confusion about the Bahr el Arab was resolved (i.e. 1908) "is not materially different from the GoS's view that 'a true understanding of which river was the Bahr el-Arab had been reached in published form in 1907.'"460
284.
The SPLM/A further notes that the GoS misinterprets the conclusions that the ABC drew from the confusion surrounding the Bahr el Arab. The GoS indeed contends that the ABC Experts concluded that "the southern boundary of Kordofan before 1905 was the Ragaba ez-Zarga"461 when, in reality, the ABC Experts considered, on the basis of the administration's understanding, that the Ragaba ez Zarga "was treated" as the provincial boundary.462
285.
The SPLM/A also dismisses the GoS's criticism of the ABC Experts' decision to include in the Abyei Area a large area north of the Ragaba ez Zarga.463 This criticism is in fact based on the wrong premise that the Abyei Area's northern boundary should necessarily be the Kordofan/Bahr el Ghazal boundary.464 instead of attempting to infer what the Condominium authorities transferred to Kordofan by reference to this putative border, the GoS should have examined what the authorities considered they had transferred.465

(iii) The Bahr el Arab as the alleged definitive boundary between Kordofan and Bahr el Ghazal prior to 1905

(x) GoS Arguments

286.
The GoS submits that a number of pre-1905 documents describe the Bahr el Arab as the provincial boundary between Bahr el Ghazal and Kordofan, including: Frank Lupton's 1884 writings;466 an 1884 report by the Intelligence Branch of the War Office;467 the 1898 first edition of the 1898 Gleichen Handbook;468 Mardon's 1903 revised map (first issued in 1901);469 the 1902 to 1904 Bahr el Ghazal Annual Reports;470 the 1904 Kordofan Annual Report (which states that "the Darfur Frontier […] runs southwards, west of Dar Homr to the Bahr el-Arab which is the northern boundary of the Bahr el-Ghazal Province");471 the 1905 Bahr el Ghazal Annual Report (which no longer refers to the provincial boundaries as being "vaguely defined");472 and the 1905 Gleichen Handbook473 which includes two maps showing the Bahr el Arab as the northern border of the Bahr el Ghazal.474
287.
According to the GoS, it is clear from the contemporary record that the boundary between Kordofan and Bahr el Ghazal before the 1905 transfer was the Bahr el Arab.475 The fact that the provincial boundaries were not prescribed in any kind of constitutional, legislative or executive document is immaterial, as no such legal requirement existed.476 Contrary to Professor Schofield's position, what mattered was that Condominium officials, including Governor-General Wingate, considered the Bahr el Arab to be the boundary.477

(y) SPLM/A Arguments

288.
According to the SPLM/A, when the Bahr el Arab was referred to in the documentary record as the provincial boundary prior to and during 1905, "the Anglo-Egyptian administrators simply did not have a clear or common understanding of where that boundary was in fact located."478
289.
The GoS itself acknowledges "that the location and course of the Bahr el-Arab was 'ill-defined,' 'vaguely-defined,' 'uncertain,' and 'bewildering.'"479 More generally, the GoS concedes that "'provincial boundaries at this period [1902-1922] were not laid down or recorded in any very formal way, and they were often stated to be approximate'"480 and fails, for want of adequate documentary support, in its attempt retrospectively to "create" a clear or official boundary between Bahr el Ghazal and Kordofan prior to 1905.481
290.
The SPLM/A also relies on Professor Schofield to argue that the three requirements for boundary delimitation, namely allocation, delimitation and demarcation, were never fulfilled.482 Since the references to the Bahr el Arab in 1905 were only approximate, there cannot have been any definitive identification of a boundary.483 There was never any governmental act identifying geographically a specific boundary line capable of being demarcated and mapped.484 Even references in official documents to the general term "Bahr el-Arab," the specific location of which was unclear, could not have constituted "a central defining action by the Condominium government allocating or establishing a boundary."485
291.
The SPLM/A goes on to contend that the cartographic evidence confirms that the boundary was indefinite and indeterminate in 1905. The SPLM/A contends that there "was no official Sudan Government map as of 1905 that delimited a provincial boundary between Kordofan and Bahr el-Ghazal; on the contrary, the only official map that existed (i.e., the 1904 Anglo-Egyptian Sudan map prepared by the intelligence office in Khartoum)486 "conspicuously omitted any such boundary, while identifying the boundaries of other Sudanese provinces."487 The 1901 Mardon map488 relied upon by the GoS does not purport to show the boundary.489 Mardon himself noted in 1906 that "'[t]he exact limits of the provinces, especially those in the south, are not yet definitely fixed."490

(iv) The alleged description in the 1905 transfer documents of the provincial boundary as the northern limit of the transferred area

(x) GoS Arguments

292.
The GoS places great emphasis on the 1905 transfer documents, namely the March 1905 SiR and the 1905 Annual Reports of the Kordofan and Bahr el-Ghazal provinces,491 both of which no longer mention the Bahr el Arab as the boundary of the two provinces,492 and the 1905 Memorandum by Governor-General Wingate, the senior government official in Sudan at the time.493
293.
According to the GoS, the relevant passage of the Wingate Memorandum494 indicates that the northern limit of the transferred area was the Bahr el Arab. Wingate, who the GoS maintains knew the exact location of the river,495 unequivocally states that the tribal districts that were incorporated in Kordofan were located south of the Bahr el Arab and had been formerly part of Bahr el Ghazal.496 There is no reference in his report to an area north of the Bahr el Arab being transferred.497
294.
The GoS also stresses that the reference to the transfer in the Wingate Memorandum is under a section entitled "Changes in Provincial Boundaries and Nomenclature"498 while in the 1905 Annual Reports of both Bahr el Ghazal and Kordofan, the transfer is discussed under the sections entitled "Provinces Boundaries."499
295.
The GoS concludes that the four transfer documents make it clear that Condominium officials transferred a territory from one province to another, bounded to the north by the Bahr el Arab.500

(y) SPLM/A Arguments

296.
According to the SPLM/A, the analysis of the transfer documents demonstrates that Governor-General Wingate himself considered that there was still uncertainty surrounding the course of the Bahr el Arab in 1905.501 He did not state that it was the provincial boundary502 and he "certainly did not purport to fix 'the northern limit of the area that was transferred in 1905.'"503 His reference to the "Bahr el-Arab" was "merely a general geographic description, and not the delimitation or definition of a boundary."504 Indeed, the provincial boundary was irrelevant to the delimitation of the northern limit of the transferred area. What occurred was a transfer of people, not territory, from the Bahr el Ghazal administration to the Kordofan administration.505 This is evidenced, in particular, by the March 1905 SIR.506
297.
It is obvious that the transfer of the Ngok and Twic people entailed territorial consequences.507 However, the boundaries of Kordofan were not extended in the years following the transfer precisely because the Condominium officials, who did not know what territory the Ngok Dinka inhabited, transferred the administration of a people rather than a specific area.508
298.
The SPLM/A therefore agrees with the ABC Experts' conclusion that "the Ngok people were regarded [by the Anglo-Egyptian administration] as part of the Bahr el-Ghazal Province until their transfer in 1905"509 and that "the government's claim that only the Ngok Dinka territory south of the Bahr el-Arab was transferred to Kordofan in 1905 is therefore found to be mistaken."510

(b) Post-1905 depictions of the alleged boundary and transferred area

(i) GoS Arguments

299.
The GoS points to the first description of the post-1905 boundary in a 1908 report issued by Captain Lloyd, then Governor of the province of Kordofan.511 While this report still identifies the Bahr el Arab as the southern boundary of Kordofan, a map published by Lloyd in 1910512 shows the border between the Kordofan and Bahr el Ghazal provinces to be south of the Bahr el Arab.513
300.
Between 1905 and 1909, no other changes were recorded regarding the location of the boundaries in the Annual Reports for the provinces of Bahr el Ghazal and Kordofan, except a minor change in the Darfur/Kordofan boundary in 1908. only the 1905 transfer can therefore justify the curved line in Lloyd's 1910 map.514 The only reason this map (and the whole series of Sheet-65 maps) labels the boundary as "approximate" is that the "southern limits of the transferred areas were not defined in 1905, either in Wingate's Memorandum or elsewhere."515
301.
The GoS also relies on the 1911 and 1912 editions of the Anglo-Egyptian Handbook.516 The former notes that the northern boundary of the Bahr el Ghazal province was not yet delimited, but indicates that "the boundary divides certain tribal districts to Lake No,"517 instead of following the Bahr el Arab. The latter describes the southern border of Kordofan, "somewhat indefinitely,"518 as following a watercourse ten miles to the east of Ghabat el Arab, as shown on the 1914 Ghabat el Arab office Map.519 The GoS submits that subsequent maps produced either by Sudan's War or Survey office all show the transferred area in the same way.520 The boundary is shown as a curved line, never more than 25 km from the Bahr el Arab, following the course of the river until it is depicted as a straight-line in 1925 to account for, inter alia, the modification of the Darfur boundary in 1924 and the re-transfer of the Twic Dinka to Bahr el Ghazal.521

(ii) SPLM/A Arguments

302.
The SPLM/A contends that Sudan Government maps did not identify any definite provincial boundary between Kordofan and Bahr el Ghazal until well after 1905.522 The Survey Office's 1907 map of northern Bahr el Ghazal523 thus omits the depiction of the boundary between the two provinces.524 Further, Lloyd's 1910 map, an unofficial map relied on by the GoS, clearly describes the boundary between Bahr el Ghazal and Kordofan to be approximate.525 It is not until 1913 that the Sudan Government itself attempted to identify the boundary in a map of Kordofan which still contained a number of inaccuracies.526
303.
The SPLM/A refers the Tribunal to Figure 14 in the GoS Memorial and Map 60 in the SPLM/A Map Atlas vol. 2, which both show the wide and continuing variations in the boundary in the first decades of the 20 th century and illustrate its indeterminate nature. The SPLM/A finally argues that "even when a Kordofan/Bahr el-Ghazal boundary was depicted between 1914 and 1930, the boundary was consistently labeled 'Approx. Province Bdy.'"527

4. The location of the nine Ngok Dinka Chiefdoms in 1905

304.
The GoS's position remains that the Abyei Area must be delimited by determining the area of the nine Ngok Dinka chiefdoms that previously fell within the province of Bahr el Ghazal and that were transferred to Kordofan in 1905. However, assuming for the sake of argument that the SPLM/A's Tribal Interpretation is right, the GoS warns that determining the area occupied and used by the nine Ngok Dinka Chiefdoms in 1905 is a very complicated question of anthropological fact.528 In any event, the SPLM/A fails in its attempt to prove any significant Ngok Dinka presence north of the Bahr el Arab/Kir in 1905.529
305.
For its part, SPLM/A maintains that the "area of the nine Ngok Dinka chiefdoms transferred to Kordofan in 1905" is proved to encompass all of the territory occupied and used by the Ngok Dinka people in 1905 extending north to 10 ° 35'N.530 Both Parties examine the location of the Ngok Dinka prior to, and after, the 1905 transfer.

(a) The location of the Ngok Dinka prior to 1905

(i) The migration to, and settlement in, the Abyei region of the Ngok Dinka in the 18 th and 19 th century

(x) GoS Arguments

306.
The GoS acknowledges that there might have been a limited presence of Ngok Dinka ancestors north of the Bahr el Arab before the 1905 transfer, but insists that this situation was short-lived.531 In this regard, the GoS relies, inter alia, on the research of scholar Stephanie Beswick532 and submits that there was never any permanent Ngok presence around the Ragaba ez Zarga, since the Dinka tribes who migrated north of the Bahr el Arab in the 18 th century were pushed back south by the Baggara before the end of that century.533
307.
The SPLM/A's reliance on Henderson and Deng to defend its claim to a pre-1905 permanent Ngok Dinka settlement around the Ragaba ez Zarga and to a boundary at 10 ° 35'N is misplaced and fails to quote Henderson's and Deng's relevant passages regarding the Ngok Dinka's movement southwards.534

(y) SPLM/A Arguments

308.
The SPLM/A stresses that Beswick, contrary to the GoS's claim, confirms that the Ngok Dinka were present well to the north of the Bahr el Arab and the Ragaba ez Zarga.535 Beswick's indication that, after their mid-1800s alliance with the Misseriya, the Ngok Dinka "returned with their herds to the Kir/Bahr el Arab River region for grazing"536 in no way suggests that the Ngok Dinka abandoned the territories north of the Bahr el Arab/Kir, but corroborates the "undisputed locations of the Ngok Dinka's dry season activities."537
309.
Further, while Deng did write that the Alei were pushed southwards under Arab pressure,538 the GoS fails to mention Deng's indication that "most of the Ngok settled on the Ngol River" and that the Alei, who remained further north, were therefore moving south from Muglad towards the Ngol/Ragaba ez Zarga.539

(ii) The effects of the Mahdiyya on the Ngok Dinka and Misseriya

(x) GoS Arguments

310.
The GoS dismisses as purely speculative the SPLM/A's claim that "...the asymmetric effects of the Mahdiyya540 on the Ngok and the Misseriya enabled the Ngok to expand their historic territories at the end of the 19th century."541 Contrary to Professor Daly's position,542 Collins and Peel show that the slave and cattle raids that had started during the Turkiyya continued during the Mahdiyya.543
311.
In addition, the GoS notes that during this period, the Baggara were not the only ones threatening the territory of the Ngok Dinkas. Indeed, there were inter-Dinkas wars and repeated raiding by the Nuers to the East.544 The GoS therefore submits that the claim that the relatively small impact of the Mahdiyya on the Ngok Dinka allowed them to migrate north has no substance.

(y) SPLM/A Arguments

312.
The SPLM/A submits that Ngok Dinka demography and occupation of the Abyei region were little affected by the Mahdiyya, while the Misseriya suffered heavy casualties in the conflict with the Anglo-Egyptian forces,545 in part because the Misseriya sided with the Mahdists.546 The SPLM/A cites Henderson547 and Deng who, relying on Henderson's conclusions, explained that "[a]lthough the Mahdiya was one of the most violent chapters in southern history, it was a relatively peaceful period for the Ngok."548 The SPLM/A infers from this that the "the Ngok would not have retreated from prior settlements in the Bahr region and that the Misseriya would have been in no position to expand at the expense of the Ngok" in the years preceding the transfer of the Abyei Area.549
313.
The SPLM/A submits that the GoS's reliance on Peel and Collins is misplaced.550 In fact, Collins even contradicts the GoS's position.551

(iii) The location of the Ngok Dinka from the late 19 th century through 1905

(x) Alleged limitations affecting the pre-1905 documentary record

(1) GoS Arguments

314.
The GoS disagrees with the SPLM/A's claim that the pre-1905 documentary record is limited by such factors as the lack of British knowledge in the region, the limited expeditions in the area and the remoteness of the zone.552
315.
In response to the SPLM/A's claim that no negative inferences can be drawn from the fact that certain British explorers did not observe any Ngok Dinka when they went to the region, the GoS argues that although it is fair not to draw negative inference based on a single visit, "the comprehensive absence of evidence" in this case becomes "evidence of absence."553 According to the GoS, "[t]here are parts of the [region] that remain, even today, permanently uninhabited. That doesn't mean they're terra nullius."554

(2) SPLM/A Arguments

316.
The SPLM/A submits that the pre-1905 documentary record is affected by many limitations and shortcomings.555 Firstly, the record is meager and sparse556 and while it does attest to Ngok Dinka presence extending north from the Bahr el Arab to, and beyond, the Ragaba ez Zarga,557 its reliability and comprehensiveness should not be exaggerated.558
317.
The SPLM/A thus points out that, at the beginning of the twentieth century, the contacts of the few Anglo-Egyptian administrators with the region "were in the nature of exploratory treks,"559 all made during the dry season, when the Ngok Dinka would move to the south of the region to graze their cattle herds. They were therefore unable to observe the Ngok Dinka's occupation and use of land in the wet season.560 The officials followed very limited routes and "virtually never ventured to the north of the Ngol/Ragaba ez-Zarga, save along a single corridor extending from Fauwel to Keilak covered by Mahon's, Wilkinson's, and Percival's treks."561 The SPLM/A also emphasizes the Anglo-Egyptian officials' lack of personnel,562 the language barrier,563 and inaccessibility of the region.564
318.
The SPLM/A identifies other factors accounting for this lack of knowledge, such as the efforts of the Ngok Dinka to conceal the location of their villages for fear of slave-raiding.565
319.
Therefore, one should not infer from the reports of the Anglo-Egyptian officials that the Ngok Dinka were located only in the places where they were observed,566 particularly when the GoS fails to provide complete copies of potentially relevant maps.567

(y) Location of the nine Ngok Dinka chiefdoms in the documentary record from the late 19th century through 1905

(1) GoS Arguments