The Nigerian Eastern Region declares independence as the Republic of Biafra, sparking a civil war.

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 in the Atlantic Ocean to the south. 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 its capital, Abuja, is located. The largest city in Nigeria by population is Lagos, one of the largest metropolitan areas in the world and the largest in Africa.

Biafara, anglicized as Biafra and officially the Republic of Biafra, was a partially recognised state in West Africa that declared independence from Nigeria and existed from 1967 to 1970. Its territory consisted of the former Eastern Region of Nigeria, predominantly inhabited by the Igbo ethnic group. Biafra was established on 30 May 1967 by Igbo military officer and Eastern Region governor Chukwuemeka Odumegwu Ojukwu under his presidency, following a series of ethnic tensions and military coups after Nigerian independence in 1960 that culminated in the 1966 anti-Igbo pogrom.

The Nigerian Civil War, also known as the Biafran War, Nigeria-Biafra War, or Biafra War, was fought between Nigeria and the Republic of Biafra, a secessionist state which had declared its independence from Nigeria in 1967. Nigeria was led by General Yakubu Gowon, and Biafra by Lieutenant Colonel Chukwuemeka "Emeka" Odumegwu Ojukwu. The conflict resulted from political, ethnic, cultural and religious tensions which preceded the United Kingdom's formal decolonisation of Nigeria from 1960 to 1963. Immediate causes of the war in 1966 included a military coup, a counter-coup, and anti-Igbo pogroms in the Northern Region. The pogroms and the exodus of surviving Igbos from the Northern Region to the Igbo homelands in the Eastern Region led the leadership of the Eastern Region to conclude that the Nigerian federal government would not protect them and that they must protect themselves in an independent Biafra.