South Sudan–Uganda border
A line of straight segments between mountain peaks, plus rivers, set in 1914 when Britain swapped land between Sudan and Uganda along the Nile. It has never been fully marked on the ground, and in July 2025 a dispute near Kajo-Keji turned deadly.
Written from cited sourcesLast checked 30 September 2026Suggest a correction
See it on the globe:South Sudan →Uganda →
The 1914 swap
After King Leopold II’s lease of the Lado Enclave ended in 1910, the land passed to the Anglo-Egyptian Sudan. A Sudanese–Ugandan commission tried to mark a boundary in 1913 but could not finish the eastern part because of the season and a lack of water.[1]
On 1 January 1914 the two British territories exchanged land. West of the Nile, Sudan gave Uganda the southern part of the former enclave, which became the West Nile District. East of the Nile, Uganda gave Sudan everything north of the 5th parallel to the Ethiopian border, so the towns of Nimule and Gondokoro became Sudanese. The new line was promulgated on 21 April 1914. In 1926 Uganda ceded the Tereteinia area to Sudan to reunite peoples the 1914 line had split.[1]
“…or such a line as shall exclude the riverain people below Nimule…”[1]
Kajo-Keji
Sudan became independent in 1956 and Uganda in 1962; in 2011 the line became South Sudan’s border with Uganda. In July 2025 fighting broke out at Nyainga Muda in South Sudan’s Kajo-Keji County. Uganda’s army said South Sudanese troops had crossed into West Nile and refused to withdraw; South Sudanese officials said Ugandan forces attacked first with tanks and artillery. Five South Sudanese soldiers and one Ugandan soldier were reported killed, and thousands of civilians fled.[2]
Both sides agreed a ceasefire and a joint investigation, and South Sudan’s army said it was working through the joint technical border committee.[2]
Timeline
191016 June 1910
Lado Enclave returned
Sudan takes over Leopold’s leased land.[1]
19141 January 1914
Land swap
West Nile goes to Uganda; Nimule to Sudan.[1]
1926
Tereteinia ceded
Uganda gives Sudan an area to reunite divided peoples.[1]
202528 July 2025
Kajo-Keji clash
Ugandan and South Sudanese forces fight over a border area.[2]
More borders
Sources
- [1]International Boundary Study No. 104: Sudan – Uganda Boundary · US Department of State, Office of the Geographer · 1 October 1970
- [2]Uganda deploys more troops after border clash in Kajo-Keji · Radio Tamazuj · 30 July 2025
Map geometry from Natural Earth via world-atlas. See credits.