Nigeria gained a degree of self-rule in 1954, and full independence from the United Kingdom on October 1, 1960, as the Federation of Nigeria with Abubakar Tafawa Balewa as its prime minister, while retaining the British monarch, Elizabeth II, as nominal head of state and Queen of Nigeria. Azikiwe replaced the colonial governor-general in November 1960. At independence, the cultural and political differences were sharp among Nigeria's dominant ethnic groups: the Hausa–Fulani in the north, Igbo in the east and Yoruba in the west. 