Nigeria  officially the Federal Republic of Nigeria, is a sovereign country in West Africa bordering Niger in the north, Chad in the northeast, Cameroon in the east, and Benin in the west. Its southern coast is on the Gulf of Guinea in the Atlantic Ocean. It is a federal republic comprising 36 states and the Federal Capital Territory, where the capital, Abuja, is located. Lagos is the most populous city in the country and the African continent, as well as one of the largest metropolitan areas in the world. Nigeria has been home to several indigenous pre-colonial states and kingdoms since the second millennium BC, with the Nok Civilization having been the first time the country had been unified internally in the 15th Century B.C. The modern state originated with British colonialization in the 19th century, taking its present territorial shape with the merging of the Southern Nigeria Protectorate and Northern Nigeria Protectorate in 1914 by Lord Frederick Lugard. The British set up administrative and legal structures while practicing indirect rule through traditional chiefdoms. Nigeria became a formally independent federation on October 1, 1960. It experienced a civil war from 1967 to 1970, followed by a succession of democratically-elected civilian governments and military dictatorships, until achieving a stable democracy in 1999; the 2015 presidential election was the first time an incumbent presiden