Ademulegun was commissioned in 1949 and was a member of the senior Officer Corps of the army along with Aguiyi Ironsi, Zakariya Maimalari and Babafemi Ogundipe.

He was considered friendly with Ahmadu Bello which brought distaste to some junior officers who frowned at their commander fraternizing with politicians.

Ademulegun and his wife were killed while in bed during the 1966 coup when they were shot by rebels led by Timothy Onwuatuegwu, an instructor at the Nigerian Military Training College.

Her account provided details of the invasion and gruesome murder of the former General Officer Commanding (GOC), 1st Division in Kaduna state.

[6] He was survived by his daughter Mrs. Solape Ademulegun-Agbi, Bankole, Kunle, Gbenga, Goke, and his oldest son Frank Bamidele who later enlisted into the Nigerian Air Force where he rose to the rank of Group Captain before he died in 2002.