Gowon joined the Nigerian Army in 1954, and received his commission as a second lieutenant on 19 October 1955, his 21st birthday. He was trained in the prestigious Royal Military Academy Sandhurst, UK (1955–56), Staff College, Camberley, UK (1962) as well as the Joint Staff College, Latimer, 1965. He saw action in the Congo as part of the United Nations Peacekeeping Force, both in 1960–61 and in 1963. He advanced to battalion commander rank by 1966, at which time he was still a lieutenant colonel.