The Nigerian Armed Forces (NAF) are the military forces of Nigeria. The armed forces consists of three service branches: the Nigerian Army, Nigerian Navy, and Nigerian Air Force. The President of Nigeria functions as the commander-in-chief of the armed forces, exercising his constitutional authority through the Ministry of Defence, which is responsible for the management of the military and its personnel. The operational head of the AFN is the Chief of Defence Staff, who is subordinate to the Nigerian Defence Minister. With a force of more than 230,000 active personnel, the Nigerian military is one of the largest uniformed combat services in Africa. According to Global Firepower, the Nigerian Armed Forces are the fourth-most powerful military in Africa, and ranked 35th on its list, internationally.
The Nigerian Armed Forces were established in 1960 as the successor to the combat units of the Royal West African Frontier Force stationed in the country, which had previously served as the British Empire's multi-battalion field force, during Nigeria's protectorate period. Since its creation, the Nigerian military has fought in a civil war – the conflict with Biafra in 1967–70 – and sent peacekeeping forces abroad, both with the United Nations and as the backbone of the Economic Community of West African States (ECOWAS) Cease-fire Monitoring Group (ECOMOG) in Liberia and Sierra Leone. It has also seized power twice at home (1966 & 1983). Nigeria's armed forces would continue to remain an active element in combat operations throughout the African continent over the proceeding decades, with
notable engagements including its 2017 involvement as part of the ECOWAS military intervention in the Gambia.
The roles of a country's armed forces are entrenched in her constitution. The defence of the territorial integrity and other core interests of the nation, form the major substance of such roles.