Colonial Nigeria is considered by some specialists to begin in 1807, when Great Britain abolished the slave trade. Generally historians trace Britain's increasing involvement through later treaties and arrangements with regional rulers. As late as 1865, Great Britain hesitated to take a more active role with the Nigerian protectorates.

It did not effectively occupy the Niger area until 1885, and then under pressure of competition from France and Germany. It administered Nigeria in separate British protectorates until 1914, when it unified the country while maintaining considerable regional autonomy among the three major regions. Progressive constitutions after World War II provided for increasing representation and electoral government by Nigerians. In October 1, 1960, Nigeria gained independence.

In 1807 the Houses of Parliament in London enacted legislation prohibiting British subjects from participating in the slave trade. The decrease in trade indirectly led to the collapse of Oyo Empire. Britain withdrew from the slave trade when it was the major transporter of slaves to the Americas. The French had abolished slavery following the French Revolution, although it briefly re-established it in its Caribbean colonies under Napoleon. It sold Louisiana to the United States in 1803, the same year that it gave up on trying to regain Saint-Domingue. By the end of the Napoleonic Wars, it ended slavery in its possessions. Between them, the French and the British had purchased a majority of the slaves sold from the ports of Oyo. The economy suffered from the decline in the slave trade, although considerable smuggling of slaves to the Americas continued for years. The political troubles in Oyo came to a head after 1817, when the transatlantic market for slaves increased but, rather than supplying slaves captured from other areas, Oyo was invaded and its people taken into slavery.

Nigeria ⁱ/naɪˈdʒɪəriə/, officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in the north. Its coast in the south lies on the Gulf of Guinea on the Atlantic Ocean. The three largest and most influential ethnic groups in Nigeria are the Hausa, Igbo and Yoruba.

In terms of religion Nigeria is roughly split half and half between Muslims in the North and Christians in the South; a very small minority practice traditional religion. Since 2002 there have been a spate of clashes, particularly in the North of the country, between government forces and the Islamists Boko Haram, militant jihadists who seek to establish sharia law.

The people of Nigeria have an extensive history. Archaeological evidence shows that human habitation of the area dates back to at least 9000 BCE. The area around the Benue and Cross River 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.