From 1960 to 1963, Nigeria was a sovereign state and an independent constitutional monarchy. Nigeria shared the monarch with Australia, Canada, United Kingdom, and certain other sovereign states. The monarch's constitutional roles were mostly delegated to the governor-general of Nigeria.
Elizabeth II was the only monarch to reign during this period. As such, she was officially titled Queen of Nigeria.
The Federation of Nigeria was a predecessor to modern-day Nigeria from 1954 to 1963. It was a British protectorate until its independence on 1 October 1960. The Federation consisted of three regions:
British rule of Colonial Nigeria ended in 1960, when the Nigeria Independence Act 1960 made the federation an independent sovereign state. Elizabeth II remained head of state as the Queen of Nigeria, as well as other dominions and commonwealth realms. Her constitutional roles in Nigeria were exercisable by the Governor-General of Nigeria. Three people held the office of governor-general during the whole existence of the Federation of Nigeria:
The governor-general of Nigeria was the representative of the monarch of the United Kingdom in Colonial Nigeria from 1954 to 1960, and after Nigerian independence in 1960, the representative of the Nigerian head of state.
The office was created on 1 October 1954, when the Colony and Protectorate of Nigeria was created as an autonomous federation within the British Empire. After independence in 1960, the governor-general became the representative of the Nigerian monarch, and the office continued to exist till 1963, when Nigeria abolished its monarchy, and became a republic.