Nonyelu') was born on 3 September 1914; eight months after Northern Nigeria and Southern Nigeria were amalgamated by Sir Fredrick Lugard.
He was, the First Federal Director of Public Prosecutions (Attorney General) of Nigeria (1960–1964) and one of the pioneers of the Nigerian Bar Association .
In 1961, G.C.
was appointed a member of Her Majesty, Queen Elizabeth II's Counsel (Queen's Counsel).
As Director of Public Prosecutions (DPP), he was responsible for instituting and conducting prosecutions or to decline to proceed further with a prosecution.
It was his responsibility to ensure a fair trial according to the rule of law.