The British colonization of Nigeria (formalized 1900–1914, ending 1960) was driven by a convergence of factors:
Nigeria's 800 km coastline and major river systems (Niger, Benue) offered deep-water ports (Lagos, Calabar, Port Harcourt) and inland navigation—critical for moving goods and projecting naval power in the Gulf of Guinea.
Britain sought to block French expansion from the west (Dahomey) and German claims in Cameroon. The 1885 Berlin Conference rules required "effective occupation" to secure claims—spurring the 1897 Benin Expedition and 1900–1903 conquest of the Sokoto Caliphate.
Christian missionaries (CMS, Catholic) preceded and accompanied colonial rule, establishing schools, hospitals, and printing presses. The British government used missionary presence to justify political control as a humanitarian mission.
Colonies were status symbols among European great powers. Nigeria's size (pop. ~18 million by 1911) and resources made it a jewel in the British Empire.
These motives intertwined; economic extraction was enabled by military conquest, legitimized by ideology, and secured by geopolitical treaties.