Three years after gaining independence, Nigeria took a significant step in its political evolution by becoming a Federal Republic on October 1, 1963. This change meant that the British monarch was no longer the Head of State of Nigeria.
Dr. Nnamdi Azikiwe, who had been Governor-General, was sworn in as the first President of the Federal Republic of Nigeria. The position of President was largely ceremonial under the parliamentary system, with executive powers remaining with the Prime Minister, Sir Abubakar Tafawa Balewa.
The 1963 Constitution replaced the 1960 Independence Constitution, establishing the Supreme Court of Nigeria as the final court of appeal, rather than the Judicial Committee of the Privy Council in London. This was a crucial milestone in establishing full legal and political sovereignty.