The Coup of 15 January 1966

On 15 January 1966 a group of army officers attempted to seize power in Nigeria's first military coup. According to the country study, the conspirators killed Prime Minister Balewa in Lagos, Samuel Akintola, premier of the Western Region, in Ibadan, and Ahmadu Bello, premier of the Northern Region, in Kaduna, as well as senior officers of northern origin. Wikipedia names Major Chukwuma Kaduna Nzeogwu among the leaders and records that the finance minister, Festus Okotie-Eboh, was also killed.

The army commander, Major General Johnson Aguiyi-Ironsi, intervened to restore discipline, suspended the constitution, dissolved the legislatures, banned political parties and formed a Federal Military Government.

The coup followed years of political crisis. According to the Library of Congress country study, the federal election campaign of December 1964 was contested by two alliances and boycotted in parts of the country; in the Western Region the election of November 1965 was followed by violence in which an estimated 2,000 people died in six months. The disputed censuses of 1962 and 1963, the split in the Action Group and the treason trial of Obafemi Awolowo had already shaken confidence in the political system, and the country study records widespread abuses: intimidation of opponents, manipulation of the courts, diversion of public funds, rigging of elections and corruption.

The coup ended the First Republic and began thirteen years of military rule. The country study notes that most of the conspirators were Igbo, and that Ironsi, also Igbo, was vulnerable to accusations of favouring the Igbo; his move towards a unitary state alarmed many northerners and led to the counter-coup of July 1966.

The coup began thirteen years of military rule and set off the chain of events, the July counter-coup, the killings in the north and the secession of Biafra, that led to the civil war (country study). Wikipedia notes that it is unclear whether President Azikiwe, who was abroad at the time, had been warned.