Uganda–Congo boundary agreement

On 3 February 1915 in London, Britain and Belgium signed an agreement on the boundary between their possessions in East Africa, on the section from the Sabinyo volcano to the watershed between the Congo and Nile basins. The agreement concluded two decades of efforts to fix the boundary between the British Uganda Protectorate and the Belgian Congo. Although war was raging in Europe and almost all of Belgium was occupied, the allies found time to settle matters left over from years before.

The legacy of Leopold II

The origins of the matter went back to the agreement that Britain concluded in May 1894 with King Leopold II, ruler of the Congo Free State. The eastern boundary of his possessions was then drawn along the 30th meridian as far as the Congo–Nile watershed. The British also leased to the King extensive territories in the Nile basin, of which he actually occupied only the Lado Enclave on the upper Nile. A further agreement, of 1906, limited this lease to the duration of his reign. After Leopold II’s death in December 1909 the enclave passed in June 1910 under the administration of the Anglo-Egyptian Sudan. The Congo, however, retained the so-called Mahagi strip, a narrow corridor leading from the watershed to the western shore of Lake Albert, with the port of Mahagi.

The 1910 settlement

A line running along a meridian fitted the lie of the land poorly. In 1906–1908 a joint British–Congolese commission mapped the borderland between Mount Ngabua, south of Lake Edward, and the Semliki river, which flows north into Lake Albert. In 1910, at a conference in Brussels, Britain, Belgium and Germany agreed that the Sabinyo volcano in the Virunga range would be the point where Uganda, the Congo and German East Africa met. The conference ended on 14 May 1910 with the signing of bilateral agreements.

The Anglo-Belgian agreement of that day traced the boundary northwards from Sabinyo. The lands west of the 30th meridian, between Sabinyo and the Semliki, passed from the Congo to Uganda. In return the Congo received an elongated strip of land stretching north-east from the 30th meridian up to the southern boundary of the Mahagi strip, together with the western half of Lake Albert. In 1911 a joint commission set up boundary pillars on the southern section, and in 1913 another commission demarcated the boundary on the ground north of Lake Albert.

What the agreement brought

The agreement of 3 February 1915 officially recognised the exchange of territories of 1910 and the boundary line demarcated by the commissions. Belgium also received the south-eastern part of the Mahagi strip. The port of Mahagi on Lake Albert thus gained a direct link with the rest of the colony through Congolese territory, and a separate corridor was no longer needed. According to an American study of 1970, the boundary is about 765 kilometres long and runs in straight sections, along rivers and watersheds, crossing Lakes Edward and Albert.

For both allies settling the boundary also had a wartime dimension. Uganda and the Belgian Congo bordered German East Africa, with which they were at war, and the Belgians, whose colonies London and Paris had guaranteed in September 1914, were preparing their colonial troops for operations against the Germans. The instruments of ratification were exchanged in London only on 20 October 1919. The line then fixed is essentially still the boundary between Uganda and the Democratic Republic of the Congo today.