Congo–Nile Divide

This point is located on the boundary between the Central African Republic and the Sudan, at the limit between the Vakaga and Haute-Kotto prefectures.

The Ironstone Plateau region between South Sudan and the DRC is cut by many streams that have formed steep and narrow valleys.

[1] The vast Sudd wetlands in South Sudan are fed by the Bahr al Jabal river that drains Lake Albert and Lake Victoria in the south, and also from ten smaller rivers flowing from the Congo–Nile divide which together provide 20 billion cubic meters of water annually.

[2] The easily traveled northern section of the divide may have been the main route for Bantu expansion to the east and south in the Iron Age.

The combination of deforestation due to seed agriculture, cattle ownership and changes in weapons technology with the introduction of iron may have allowed Bantu-speakers to migrate south through the region into Buganda no more than 1,500 years ago.

The line ran through the territory of the Zande people, who lived in the dense woodland in the extreme southwest of what is now South Sudan and northeast of what is now the Democratic Republic of the Congo.

Their research and follow-up explorations by David Livingstone and Henry Morton Stanley established among Europeans that this was not the case.

[14] Other European explorers who helped map out the region included Panayotis Potagos (1839–1903), Georg August Schweinfurth (1836–1925), who discovered the Uele River, although he mistakenly thought it flowed into the Chad Basin rather than the Congo, Wilhelm Junker (1840–1892), who corrected Schweinfurth's hydrographical theories, and Oskar Lenz 1848–1925).

[1] Under an agreement of 12 May 1894 between Britain and King Leopold II of Belgium, the sphere of influence of Leopold's Congo Free State was limited to "a frontier following the 30th meridian east of Greenwich up to its intersection by the watershed between the Nile and Congo and hence following the watershed in a northerly and north-westerly direction.

France and Britain made a friendly agreement in 1919 to define the boundary between the Anglo-Egyptian Sudan and French Equatorial Africa.

[17] The section along the divide from the 11th to 5th parallel, where French Equatorial Africa met the Belgian Congo, was densely wooded and uninhabited.

The technique was to march along a compass bearing until a stream was reached, then to follow it up to its ultimate source, which was often a marsh, and to determine its location.

Congo Basin with the divide between it and the Nile Basin to the east highlighted in green.
Azande people c. 1880. Their territory lay on either side of the northern section of the divide, which was made an international frontier at the Berlin Conference of 1884–85.
The Congo–Nile divide (green line) starts at the triple divide (orange dot) where the Congo, Chad and Nile basins meet. This point is located on the boundary the Central African Republic and Sudan , at the limit between the Vakaga and Haute-Kotto prefectures.
Ruwenzori Mountains in the central part of the divide, to the west of the Albertine rift
Mountains in Rwanda. The volcanoes in the background are the Virunga Mountains , home of the critically endangered mountain gorillas .
An 1827 map, where the Congo basin was thought to be much smaller, and the Nile to originate in the Mountains of the Moon , to the west of today's South Sudan. The coastline is depicted accurately, but the interior and the Great Lakes were unknown.