The long transitional period from 1814 to 1876 was dominated by the triumph of legitimate trade and the recurring cycle of sovereignty disputes. It ended with the rise of colonial imperialism, which plunged France, Britain, and Portugal into a process of military conquest and the partition of Senegambia.

It was a violent process, conducted by regular armies from metropolitan Europe reinforced by local recruits. The immediate objective was territorial conquest. A useful distinction may be made between the conquest of northern Senegambia and that of the south. The former was entirely dominated by France. In southern Senegambia, however, the process of partition involved considerable competition between France, Britain, and Portugal. That circumstance left a profound imprint on the outcome. In every case, the acquisition of territory unleashed a continent-wide storm of violence in which formerly sovereign states were subjugated. The ferocity of inter-European rivalry eventually found a resolution in the 1885 Berlin Conference. That conference was convened for the purpose of defining rules for the partition process in the hope of averting a generalised conflict in metropolitan Europe.

French colonial imperialism in northern Senegambia

France was the sole power involved in the conquest of northern Senegambia. Beginning in the early 1850s, France reinforced its position through Faidherbe's conquests in the Senegal valley, starting from Saint-Louis and going along the seaboard from Kajoor to Saalum, with Gorée as the base.