Nigeria, officially named the Federal Republic of Nigeria, is a country in West Africa and the most populous country in Africa. Nigeria shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in the north. Its coast lies on the Gulf of Guinea, part of the Atlantic Ocean, in the south. Since 1991, its capital has been the centrally-located city of Abuja; previously, the Nigerian government was headquartered in the coastal city, Lagos.
The people of Nigeria have an extensive history, and archaeological evidence shows that human habitation of the area dates back to at least 9000 BC. The Benue-Cross River area is thought to be the original homeland of the Bantu migrants who spread across most of central and southern Africa in waves between the 1st millennium BC and the 2nd millennium AD.
On October 1, 1960, Nigeria gained its independence from the United Kingdom, and now consists of 36 states and the federal capital territory. Nigeria re-achieved democracy in 1999 after a sixteen-year interruption; from 1966 until 1999, Nigeria had been ruled (except the short-lived second republic, 1979-1983) by military dictators who seized power in coups d'état and counter-coups during the Nigerian military juntas of 1966-1979 and 1983-1998.