Guinea–Sierra Leone border

Freetown and French Guinea

Freed slaves settled at Freetown in 1787, and the settlement became a British crown colony in 1808, with a protectorate over the hinterland in 1896. France pushed into what is now Guinea in the late 19th century. An Anglo-French convention of 1882 ran a line inland from the Atlantic, and later arrangements extended it; an agreement of 21 January 1895 fixed the present boundary from the coast to Timbekundu, the source of the Niger.^[1]

For the northern stretch the 1895 agreement used the watershed between the Niger basin and the rivers flowing west to the Atlantic. Commissions surveyed and marked the line in 1895–96 and again in 1903. In 1911 Liberia’s Kailahun area was transferred to Sierra Leone, moving the tripoint with Guinea east.^[1]

“watershed separating the basin of the Niger on the one hand from the basins of the Little Scarcies and other rivers, falling westward to the Atlantic Ocean on the other hand”^[1]

Yenga

Guinea became independent on 2 October 1958 and Sierra Leone on 27 April 1961.^[1] During Sierra Leone’s civil war, Guinean troops moved into Yenga, a village in Kailahun district near the Liberian tripoint and close to diamond-mining areas, to help fight the Revolutionary United Front, and stayed after the war ended in 2002.^[2]

In September 2004 Presidents Ahmad Tejan Kabbah and Lansana Conté signed a communique, citing a 1912 treaty between Britain and France, that declared: “The village of Yenga belongs to Sierra Leone.”^[2]

In February 2026 Guinea detained 16 Sierra Leonean soldiers and police. Guinea said they had crossed about 1.4 km into its Faranah region and raised their flag; Sierra Leone said they were building a border post at Kalieyereh, on its own territory. ECOWAS and the Mano River Union sent fact-finding missions, and Guinea released the men days later. Africanews reported that the area had been contested for more than 20 years, claimed by Sierra Leone but with Guinean soldiers stationed on the ground.^[3][4]