The Federation of Nigeria was a predecessor to modern-day Nigeria. It existed between 1 October 1960 and 1 October 1963.
When British rule ended in 1960, Nigeria Independence Act 1960 transformed the Federation of Nigeria into an independent sovereign Commonwealth realm. Nigeria shared the Sovereign (British monarch Elizabeth II) with the other Commonwealth realms. The monarch's constitutional roles were mostly delegated to the Governor-General of Nigeria. The royal succession was governed by the English Act of Settlement of 1701.
The Federal Republic of Nigeria came into existence on 1 October 1963. The monarchy was abolished and Nigeria became a republic within the Commonwealth. Following the abolition of the monarchy, former Governor-General Nnamdi Azikiwe became President of Nigeria.