General Yakubu Gowon created twelve states out of the four regions that existed at that time appointing a governor to head them. The following were the governors There is an explanation video available below.
The Civilian government of Alhaji Abubakar Tafawa Balewa was ousted in a bloody coup led by major Chukwuma Nzeogwu in January 15, 1966. This first Military Coup in Nigeria then brought in Major General J.T.U Aguiyi Ironsi as the first Military Head of State of Nigeria On December, 31,1983, the civilian government of Shehu Shagari was overthrown by General Muhammed Buhari and Tunde Idiagbon when they were at Mecca.. There is an explanation video available below.