The island is the site where the capital Conakry was built on.
The island was placed under a French protectorate by the king of Dubréka on 20 January 1880.
This step was aimed to counter the English influence growing in the region.
On 24 December 1885, the Germans renounced to be established on the Island of Tombo and obtain a territory at the border between Togo and Dahomey.
The island became a French territory after its acquisition on 8 June 1889.