Covers the First Sudanese Civil War and 1972 Addis Ababa Agreement as background, the Comprehensive Peace Agreement of 2005, the January 2011 referendum, independence and UN admission in July 2011, and the 2013–2018 civil war and the 2018 Revitalised Agreement through the March 2025 detention of Riek Machar. Casualty figures for both Sudanese civil wars are heavily disputed and presented as attributed estimates.
South Sudan, in East Africa, became independent from Sudan on 9 July 2011 following a self-determination referendum provided for by the 2005 Comprehensive Peace Agreement, which had ended the twenty-two-year second Sudanese civil war (1983-2005), itself following the First Sudanese Civil War (1955-1972) and the short-lived autonomy created by the 1972 Addis Ababa Agreement.[1][2] SPLM/A founder John Garang died in a helicopter crash on 30 July 2005, three weeks after the CPA's signing; Salva Kiir succeeded him and led South Sudan through independence.[3][4] Southern Sudanese voters chose secession by an overwhelming majority in a UN-observed referendum in January 2011, and South Sudan was admitted to the United Nations as its 193rd member five days after independence.[5][6] Less than three years later, in December 2013, a conflict between the government and opposition forces broke out and continued until a Revitalised peace agreement in September 2018; that agreement was itself thrown into crisis in March 2025 by the detention of First Vice-President Riek Machar.[7][8][9]
History
From the second Sudanese civil war through the Comprehensive Peace Agreement, the 2011 referendum and independence, to the 2013–2018 civil war and the 2018 Revitalised Agreement.
651 words · 3 min read
· Agreement
The Addis Ababa Agreement ended the First Sudanese Civil War and created the Southern Sudan Autonomous Region; its 1983 abolition triggered the second civil war.
Significance here: Ended the first civil war and established the autonomy arrangement whose 1983 collapse led to the war that produced South Sudan's eventual independence.
· Agreement
The Government of Sudan and the Sudan People's Liberation Movement/Army signed the Comprehensive Peace Agreement in Naivasha, ending the twenty-two-year second Sudanese civil war and providing for a referendum on Southern Sudan's self-determination.
Significance here: Ended the second Sudanese civil war and created the legal basis for the 2011 referendum.
· Other
SPLM/A leader John Garang died in a helicopter crash three weeks after being inaugurated First Vice-President of Sudan; Salva Kiir succeeded him.
Significance here: A major leadership transition in the movement that had just secured the CPA, shaping the SPLM/A's leadership through independence and beyond.
· Referendum or popular consultation
Southern Sudanese voted 9–15 January 2011 on whether to remain united with Sudan or secede; international observers judged the process credible and the vote produced an overwhelming majority for secession.
Significance here: The vote whose result led directly to South Sudan's declaration of independence and UN membership.
· Declaration
South Sudan was proclaimed an independent state on 9 July 2011, the scheduled end of the Comprehensive Peace Agreement's Interim Period.
Significance here: Formal statehood following the referendum result.
· Recognition
Following the Security Council's recommendation, the General Assembly admitted the Republic of South Sudan as the 193rd member of the United Nations.
Significance here: Formal international recognition of South Sudanese statehood following independence.
Each number marks a specific claim. Notes give the source, its locator and how it relates to the claim.
Claim: On 9 January 2005 the National Congress Party and the Sudan People's Liberation Movement/Sudan People's Liberation Army signed the Comprehensive Peace Agreement, ending the second Sudanese civil war of 1983–2005 and opening a six-year Interim Period beginning 9 July 2005, during which the two parties formed a Government of National Unity and Southern Sudan gained regional autonomy.
Claim: The Addis Ababa Agreement, signed 27 February 1972, ended the First Sudanese Civil War and created the Southern Sudan Autonomous Region with its own legislature and executive, integrating Anya-Nya fighters into the national army; President Gaafar Nimeiry abolished this autonomous region on 5 June 1983, an act that triggered the Second Sudanese Civil War.
Claim: John Garang, who had founded and led the SPLM/A since 1983 and had been inaugurated First Vice-President of Sudan under the CPA three weeks earlier, died on 30 July 2005 in a helicopter crash while returning from a meeting with Ugandan President Yoweri Museveni; the crash was attributed to pilot error.
Claim: Salva Kiir Mayardit, an SPLM/A co-founder and military commander, succeeded John Garang as First Vice-President of Sudan on 11 August 2005 and as leader of the SPLM.
Claim: The Southern Sudan Referendum Commission's Final Results Report of 7 February 2011 recorded a turnout of 97.58%; 98.83% of valid votes cast were for secession, with invalid ballots at 0.2% and blank ballots at 0.16% of total votes cast, and 3,837,406 valid votes out of 3,851,994 total votes cast.
Claim: The UN General Assembly decided to admit the Republic of South Sudan to membership in the United Nations at its 108th plenary meeting on 14 July 2011, following the Security Council's recommendation of 13 July 2011; South Sudan became the 193rd UN member state.
Claim: The Security Council expressed grave alarm regarding the conflict between the Government of the Republic of South Sudan and opposition forces since December 2013, which emanated from internal political disputes among the country's political and military leaders, and which had resulted in significant loss of life and the displacement of two million people by the time of the resolution; the Council endorsed Cessation of Hostilities Agreements signed on 23 January and 6 and 9 May 2014.
Claim: The Revitalised Agreement on the Resolution of the Conflict in the Republic of South Sudan (R-ARCSS) was signed on 12 September 2018 in Addis Ababa, according to an independent conflict-research account; the UN Security Council also refers to it as "the 2018 'Revitalised Agreement.'" Attributed to ACCORD
Claim: On 26 March 2025, First Vice-President Riek Machar was detained and placed under house arrest in Juba on charges including treason, accused of plotting rebellion; this was widely reported to have effectively collapsed the unity government formed under the 2018 Revitalised Agreement, risking renewed civil war amid famine conditions reported to affect 7.7 million people. As of a September 2025 report, Machar remained on trial on treason and crimes-against-humanity charges.
Claim: The First Sudanese Civil War, fought from 1955 between the Sudanese government and southern Anya-Nya rebels, is estimated by a general-reference source to have killed between 500,000 and 1,000,000 people.
Claim: The Security Council resolution establishing the UN Mission in the Republic of South Sudan (UNMISS) records "the establishment of the Republic of South Sudan on 9 July 2011 upon its proclamation as an independent state," and the resolution itself took effect on that date.