Republic of, African state proclaimed in 1967 when fears that Nigerian central government was increasingly in the hands of the rival Hausa tribe led the predominantly Ibo Eastern Region of Nigeria to secede under Lt Col Odumegwu Ojukwu. On the proclamation of Biafra, civil war ensued with the rest of the federation. In a bitterly fought campaign federal forces confined the Biafrans to a shrinking area of the interior by 1968, and by 1970 Biafra ceased to exist.