Angola–Republic of the Congo border
The northern edge of Cabinda, an Angolan province cut off from the rest of the country by a strip of the Democratic Republic of the Congo. Portugal and France drew the line in 1886 and 1901, and Cabinda’s oil has kept a separatist movement alive ever since Angola’s independence.
Written from cited sourcesLast checked 29 September 2026Suggest a correction
See it on the globe:Angola →Republic of the Congo →
Portugal north of the Congo
Portugal’s hold north of the Congo River was long intermittent: it occupied Cabinda in 1783 but was forced out by a French expedition eleven months later, and claimed it again in 1815. In February 1885, during the Berlin Conference, a treaty with King Leopold’s International Association of the Congo recognised Portuguese Cabinda, while Portugal guaranteed the Association a narrow corridor to the coast.[1]
France, whose explorer Pierre Savorgnan de Brazza had signed treaties on the Congo in the early 1880s, recognised the claim too. A Franco-Portuguese convention of 12 May 1886 drew the line from Ponta Chamba near the sea along a median line between two rivers, and an arrangement of 23 January 1901 carried it along ridges to the Chiloango. Pillars A to J mark it.[1]
“follow a line beginning at Ponta Chamba, situated at the confluence of the Loema (or Louisa–Loango) and the Lubinda”[1]
Cabinda
The Republic of the Congo became independent on 15 August 1960.[1] Cabinda was recognised at Berlin as a Portuguese possession separate from Angola, but Portugal later merged it administratively with Angola. When Portugal withdrew in 1975, the Alvor Agreement with Angola’s liberation movements left Cabindans unrepresented, and Cabinda became part of Angola, chiefly for its offshore oil. The Front for the Liberation of the Enclave of Cabinda has called for independence ever since.[2]
Timeline
188514 February 1885
Treaty with Leopold’s Association
Portuguese Cabinda is recognised; the Congo corridor is created.[1]
188612 May 1886
Franco-Portuguese convention
The coastal part of the line is drawn.[1]
190123 January 1901
Inland line
The boundary is carried to the Chiloango.[1]
196015 August 1960
Congo independent
The Republic of the Congo is proclaimed.[1]
1975
Alvor Agreement
Cabinda becomes part of independent Angola.[2]
Sources
- [1]International Boundary Study No. 105: Angola (Cabinda) – Republic of the Congo (Brazzaville) Boundary · US Department of State, Office of the Geographer · 15 October 1970
- [2]Ever wonder why Africa’s borders appear so strange? · Al Jazeera · 23 February 2025
Map geometry from Natural Earth via world-atlas. See credits.