In the early hours of 15 January 1966, a group of mostly Igbo majors led by Patrick Chukwuma Kaduna Nzeogwu and Emmanuel Ifeajuna launched coordinated coups in Lagos, Kaduna and Ibadan. Prime Minister Tafawa Balewa, Premier Ahmadu Bello of the North, Premier Samuel Akintola of the West, and Finance Minister Festus Okotie-Eboh were killed. The coup failed to take full power; what followed was Major-General Aguiyi-Ironsi assuming control, a counter-coup in July 1966, the killing of Ironsi, the elevation of Yakubu Gowon, the September–October 1966 pogroms in the North, and ultimately the Civil War.
Figure 1
January 15, 1966 — killed during the coup, by city and category
Sardauna, Balewa, Akintola, Okotie-Eboh and seven senior officers were dead by dawn. The pattern of victims — Northern and Western political leadership — set the next year's politics.
Source: Madiebo, The Nigerian Revolution and the Biafran War (1980); Ademoyega, Why We Struck (1981); Siollun, Oil, Politics and Violence (2009).