Organized by South Sudanese military commander and politician George Athor, the conflict mainly took place in the states of Upper Nile and Jonglei as well as some border areas.

The rebellion was launched by Athor when he was defeated in the 2010 South Sudanese general election, rejecting the results and using his private army to battle the government.

Over the course of the conflict, Athor rejected a number of deals offered by the government, and a ceasefire agreement reached in January 2011 quickly fell apart.

[9] Athor was subsequently posted to Upper Nile, where he was involved in various factional clashes and gradually promoted until becoming lieutenant general, 8th Division commander in Jonglei, and SPLA deputy chief of staff for political and moral orientation.

[8] For the 2010 South Sudanese general election, Athor resigned from his SPLA position and ran as an independent candidate for the Jonglei governorship.

[7] In addition, Lou and Jikany Nuer youths rallied to his uprising, mostly to gain access to weapons for their own tribal conflicts against the Murle people.

[11] When Athor's defeat in the election was announced, his forces attacked a SPLA base at Doleib Hill, southwest of the Upper Nile state capital Malakal, on 30 April 2010.

[10] At first, Athor denied that he or his followers were responsible for the Doleib Hill attack, while also claimining that the SPLM had rigged the Jonglei election and harassed his supporters, demanding that Kuol Manyang step down as governor.

[10] In the same month, South Sudanese President Salva Kiir Mayardit granted amnesties to several rebel leaders, including Athor, Gatluak Gai, and Gabriel Tanginye.

Athor claimed that the government army had attacked his contingents at Dor, Koliet, and Kolnyang in Fangak, places where his rebels has assembled to wait for their integration into the military.

[8] Another regional dissident commander, Gabriel Tanginye, reportedly allied with Athor around this time; his forces subsequently began to clash with the SPLA in Fangak County.

[22] In the next month, Athor armed 1,000 Gawaar Nuer and Padeng Dinka youths for their own conflict with the Murle; in return, the militants promised to aid his operations.

[23] By November 2011, Athor's forces had been largely dislodged from northern Jonglei, though they still maintained some presence in the counties of Ayod, Fangak, Pigi and possibly Akobo.

[21] His influence in Akobo had greatly declined, however, as many Luo Nuer militants had split from his forces in order to protect their homes from attacks by Murle militias.

[24] On 19 December 2011, Athor was killed by the SPLA,[25] reportedly when he attempted to enter South Sudan's Central Equatoria from Uganda[14][26] or the Democratic Republic of the Congo.

[2] According to Vice President Machar, Athor had attempted to recruit new members for the SSDM/A in the region, but SPLA border guards had encountered the rebel leader's group in Morobo County, opened fire, and killed him and one other insurgent.

[15] It was eventually confirmed that Athor had been in frequent contact with the Sudanese government which had smuggled arms to him; in one incident, a Sudan Airways helicopter had been used for this purpose.