Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea to the south in the Atlantic Ocean. It covers an area of 923,769 square kilometres (356,669 sq mi). With a population of more than 230 million, it is the most populous country in Africa, and the world's sixth-most populous country. Nigeria borders Niger in the north, Chad in the northeast, Cameroon in the east, and Benin in the west. Nigeria is a federal republic comprising 36 states and the Federal Capital Territory, where the capital, Abuja, is located. The largest city in Nigeria is Lagos, one of the largest metropolitan areas in the world and the largest in Africa.
Nigeria has been home to several indigenous pre-colonial states and kingdoms since the second millennium BC, with the Nok civilization in the 15th century BC marking the first internal unification. 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 the Northern Nigeria Protectorate in 1914. The British set up administrative and legal structures while practicing indirect rule through traditional chiefdoms.