Nigeria In 1960, Nigeria became independent from British rule, but remained a member of the British Commonwealth. One year later, the northern section of British Cameroon was incorporated into the newly independent state that adopted the name Federal Republic of Nigeria. The history of independent Nigeria came to be marked by divisions between the Muslim North and the Christian and Animist South as well as inter-ethnic tensions.

In January 1966, an Igbo dominated military faction staged a coup d'état that soon prompted a countercoup by members of the military, who feared Igbo domination. The intrastate armed conflict terminated civilian rule with the installation of General Yakubu Gowon as president. In the late 1970s, President Gen. Olusegun Obasanjo initiated the return to civilian rule and was succeeded by Alhaji Shehu Shagari, the winner of the 1979 elections. The Second Republic lasted only from 1979 to 1983. After another 15 years of military government, civilian rule returned with the presidential elections of 1999. Former General Olusegun Obasanjo ruled the country for two presidential terms. He was succeeded by Umaru Yar'Adua, who won the 2007 elections that reportedly saw widespread vote-rigging.

In 1967, another intrastate conflict broke out when the self-proclaimed Republic of Biafra, formed by the three states of the Eastern region, declared its secession. After a massive government attack, the militarily inferior rebel forces formally surrendered to the government in early 1970.

In 1996, a long-lasting border dispute with neighbouring Cameroon over the oil-rich Bakassi peninsula culminated in a short interstate conflict. Both countries had strong cultural ties to the area, which had successively been assigned to both of the countries in the colonial era. The International Court of Justice awarded the area to Cameroon. However, the Nigerian troops did not withdraw until 2006 and sporadic border clashes continued after the end of the interstate armed conflict.

In 2004, the government of Nigeria became involved in two territorial intrastate conflicts: Ahlul Sunna Jamaa (Followers of the Prophet) strived for the establishment of an independent Islamic state in Northern Nigeria, while the NDPVF (Niger Delta People's Volunteer Force), formed by ethnic Ijaws inhabiting the oil-rich Niger Delta, strived for Ijaw self-determination and their right to control - or at least benefit from - the vast oil resources near their homes.

As civilian rule returned in 1999 ushering in political liberalisation inter-ethnic tensions heightened in Nigeria and a vast number of non-state armed conflicts erupted in the 2000s.

Both the government of Nigeria and the Bakassi Boys, a vigilante group active in some regions in the south-east, have been recorded as one-sided actors.

Since 1946 Nigeria has experienced the interstate, intrastate, non-state and one-sided categories of UCDP organised violence.