French Cameroun became independent in January 1960, and Nigeria was scheduled for independence later that same year, which raised question of what to do with the British territory. After some discussion (which had been going on since 1959), a plebiscite (British Cameroons referendum) was agreed to, and held on 11 February 1961. The Muslim-majority Northern area opted for union with Nigeria, and the Southern area voted to join Cameroon.
Northern Cameroons became a region of Nigeria on 31 May 1961, while Southern Cameroons became part of Cameroon on 1 October. In the meantime, the area was administered as a French Colony, in French West Africa.