The days of the army were always present in those days. One military followed another, one coup after another, with the exceptional period of the layman Shehu Shagari, who was a poet, not a soldier.
One of the soldiers from the beginning in the independent Nigeria Army was Zakariya Maimalari, who was killed in the coup of 1966. Haruna Poloma has written a biography on this soldier who rose through the ranks. At the presentation of the book two former presidents (and army men) were present. Gowon who was leading Nigeria from 1966 till 1975. The other one was Obasanjo who played an important military role in the war with Biafra (My Command), who later became president and elder statesman in Africa.
For more information on this presentation reads here.