 He has participated in several military coups, and played a central role in founding the Fourth Nigerian Republic.He was most recently the Minister of Defence, and has served as National Security Adviser to three presidents; he was also the Chief of Army Staff during Ernest Shonekan and briefly Sani Abacha's regime, headed different intelligence agencies, and was commander of the Nigerian Defence Academy.Aliyu Mohammed was born on 18 May 1943 in Gusau, Zamfara State.