Cameroon–Nigeria border

British and German spheres

Germany proclaimed a protectorate over Kamerun on 15 July 1884, and Britain one over the Oil Rivers, the coast of what became southern Nigeria, in June 1885. An arrangement that year split their spheres along the Rio del Rey on the coast; in 1890 they admitted that no river matching the one marked on the maps existed there, and adopted a provisional line from the head of Rio del Rey Creek instead.^[1]

Further agreements carried the line north. In 1893 it was run to Yola on the Benue, and around the town along the arc of a circle centred on it, and then on to Lake Chad; a 1906 agreement redrew the northern section, and agreements of 11 March and 12 April 1913 described the line in detail from Yola to the sea.^[1]

“no river exists on the Gulf of Guinea corresponding with that marked on Maps as the Rio del Rey”^[1]

The British Cameroons

British and French forces occupied Kamerun in the First World War and divided it in 1919. Britain ran its strip, the Northern and Southern Cameroons, as part of Nigeria. An Anglo-French exchange of notes in 1931 fixed the line between the British and French parts from Lake Chad south, and in 1946 Britain drew a line between its Northern and Southern Cameroons.^[1]

In plebiscites on 11 February 1961, the Southern Cameroons voted to join the newly independent Republic of Cameroun and the Northern Cameroons to join Nigeria. The old colonial lines became today’s border.^[1]

The World Court and Bakassi

On 10 October 2002 the International Court of Justice fixed the boundary from Lake Chad to the sea in a final, binding judgment. It confirmed the colonial instruments, the 1931 notes in the north, the 1946 order in the middle and the 1913 agreements in the south, and interpreted them sector by sector. Under the 1913 agreement it found that sovereignty over the Bakassi Peninsula lay with Cameroon.^[2]

The court asked Nigeria to withdraw its administration and forces from Bakassi and from the part of the Lake Chad area that it found to be Cameroonian, and each side to withdraw from land belonging to the other along the rest of the line. It noted Cameroon’s pledge to keep protecting Nigerians living in Bakassi and around Lake Chad.^[2]

Under the UN-backed Greentree Agreement of June 2006, Nigeria formally ceded Bakassi in 2008. A five-year transition ended on 14 August 2013, when Cameroon took full sovereignty, and the UN envoy for West Africa called the process a good example of preventive diplomacy.^[3]