Major General Johnson Thomas Umunnakwe Aguiyi-Ironsi MVO, MBE (3 March 1924 – 29 July 1966) was the first Military Head of State of Nigeria. He seized power amidst the ensuing chaos following the 15 January 1966 military coup, which decapitated the country's leadership.[1]

He ruled from 16 January 1966 until his assassination on 29 July 1966 by a group of mutinous Northern Nigerian officers and men who were led by Major Murtala Mohammed and included Captain Theophilus Danjuma, Lieutenant Muhammadu Buhari, Lieutenant Ibrahim Babangida and Lieutenant Sani Abacha in a revolt against his government in what was popularly called the July Counter Coup.[2]