In July 1966 Lieutenant Muhammadu Buhari was one of the participants in the "July Rematch" or so called "Counter-Coup", led by Lt-Col Murtala Muhammed, that overthrew and assassinated Nigeria's first self-appointed military Head of State General Aguiyi Ironsi, who had assumed leadership of the Nigerian government after a failed coup attempt on 15 January 1966, which overthrew the elected parliamentary government of Nigeria (also known as first republic).