Educated at the Government Secondary School, Tamale, 1954-1948.
He enlisted in the Ghana army in 1959 and was selected for cadet training at Teshie before going to the Indian Military Academy at Dehra Dun from 1960 to 1962. He was a platoon commander with the Ghana forces on the UN Peace Keeping mission in the Congo (Zaire) in 1962 and later assistant liaison officer at the UN Headquarters in Kinshasa. He returned home to become company commander of the 5th Battalion and was promoted to Deputy Assistant Adjutant-General in the Ministry of Defence (1966-7) and Brigade Major of the 1st Infantry Brigade Group in Accra (1967-8). From 1968 to 1969 he was second in command of the 6th Bat-talion. From 1970 until the advent of the coup in January 1972, he was lieutenant-colonel commanding the 3rd Battalion of Infantry at Sunyani, the capital of Brong Ahafo, between Accra and Kumasi, and gave his full support to the coup.
His name was on the first list of members of the National Redemption Council announced by Colonel Acheampong on the morning of January 13. He led the Ghana delegation to Guinea in May to arrange for the return of President Nkrumah’s body after his death in exile. He was first appointed Commissioner of NRC Affairs shortly after the coup but on January 9, 1973, was made Commissioner for Information.
A lieutenant-colonel, not involved in the original planning of the coup, but his resolution, loyalty to his colleagues and belief in its principles was demonstrated at the time of the take-over.
He was in charge of the 3rd Battalion at Sunyani, halfway between Accra and the Ashanti homeland of Dr Busia. General Afrifa had gone to Ashanti to raise a counter coup force and phoned to get Colonel Benni’s support. He turned him down categorically.