The Nigeria Regiment, Royal West African Frontier Force, was formed by the amalgamation of the Northern Nigeria Regiment and the Southern Nigeria Regiment on January 1, 1914. At that time, the regiment consisted of five battalions:
The Regiment served throughout First World War in the Cameroons (1914-1916), and in East African Campaign (1916-1918). In the Second World War, the regiment saw service in the East African Campaign where it carried out the fastest advance in military history against Italian forces and in Burma where it provided the bulk of the 81 and 82 West African divisions. In addition 3 West African Brigade was attached throughout the Second Chindits operation of 1944. In 1956, at the time of the visit of Queen Elizabeth II, the regiment was renamed The Queen's Own Nigeria Regiment, Royal West African Frontier Force.
There was eventually a Nigeria Regiment Training Centre at Zaria, a field company of engineers, and a field battery of artillery. In its last years the battalions were stationed in Kaduna (Kano), Enugu, Ibadan, and Abeokuta (one each); these rotated stations.
Until shortly before independence in 1960 there was still a majority of British officers, and some specialist British NCOs. Johnson Aguiyi-Ironsi was commissioned as early as 1949 (with the result that he later became the first Nigerian General Officer Commanding of the Army and the first military head of state), but the number of African officers rose only slowly during the 1950s.