a republic in West Africa, on the Gulf of Guinea: Lagos annexed by the British in 1861; protectorates of Northern and Southern Nigeria formed in 1900 and united as a colony in 1914; gained independence as a member of the Commonwealth in 1960 (membership suspended from 1995 to 1999 following human rights violations); Eastern Region seceded as the Republic of Biafra for the duration of the severe civil war (1967–70); ruled by military governments from 1966 to 1999. It consists of a belt of tropical rain forest in the south, with semidesert in the extreme north and highlands in the east; the main export is petroleum. Official language: English; Fulani, Hausa, Ibo, and Yoruba are the chief regional languages. Religion: animist, Muslim, and Christian. Currency: naira. Capital: Abuja. Pop: 190 886 311 (2017 est). Area: 923 773 sq km (356 669 sq miles)