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Military coups

On 15 January 1966, Major Chukuma Kaduna Nzeogwu, Major Emmanuel Ifeajuna, and other junior Army officers (mostly majors and captains) attempted a coup d'état. The two major political leaders of the north, the Prime Minister, Sir Abubakar Tafawa Balewa and the Premier of the northern region, Sir Ahmadu Bello were killed by Major Nzeogwu. Also murdered was Bello's wife and officers of Northern extraction. The President, Sir Nnamdi Azikiwe, an Igbo, was on an extended vacation in the West Indies. He did not return until days after the coup. There was widespread suspicion that the Igbo coup plotters had tipped him and other Igbo leaders off regarding the pending coup. In addition to the killings of the Northern political leaders, the Premier of the Western region, Ladoke Akintola and Yoruba senior military officers were also killed. This "Coup of the Five Majors" has been described in some quarters as Nigeria's only revolutionary coup. This was the first coup in the short life of Nigeria's nascent second democracy. Claims of electoral fraud were one of the reasons given by the coup plotters. Besides killing much of Nigeria's elite, the Coup also saw much of the leadership of the Nigerian Federal Army killed with seven officers holding the rank above colonel killed. Of the seven officers killed, four were northerners, two were from the southeast and one was from the Midwest. Only one was an Igbo.

This coup was, however, not seen as a revolutionary coup by other sections of Nigerians, especially in the Northern and Western sections and by later revisionists of Nigerian coups. Some alleged, mostly from Eastern part of Nigeria, that the majors sought to spring Action Group leader Obafemi Awolowo out of jail and make him head of the new government. Their intention was to dismantle the Northern-dominated power structure but their efforts to take power were unsuccessful. Johnson Aguiyi-Ironsi, an Igbo and loyalist head of the Nigerian Army, suppressed coup operations in the South and he was declared head of state on 16 January after the surrender of the majors.

In the end though, the majors were not in the position to embark on this political goal. While their 15th January coup succeeded in seizing political control in the north, it failed in the south, especially in the Lagos-Ibadan-Abeokuta military district where loyalist troops led by army commander Johnson Aguyi-Ironsi succeeded in crushing the revolt. Apart from Ifeajuna who fled the country after the collapse of their coup, the other two January Majors, and the rest of the military officers involved in the revolt, later surrendered to the loyalist High Command and were subsequently detained as a federal investigation of the event began.

Aguyi-Ironsi suspended the constitution and dissolved parliament. He abolished the regional confederated form of government and pursued unitary policies favoured by the NCNC, having apparently been influenced by NCNC political philosophy. He, however, appointed Colonel Hassan Katsina, son of Katsina emir Usman Nagogo, to govern the Northern Region, indicating some willingness to maintain cooperation with this bloc. He also preferentially released northern politicians from jail (enabling them to plan his forthcoming overthrow). Aguyi-Ironsi rejected a British offer of military support but promised to protect British interests.

Ironsi fatally did not bring the failed plotters to trial as required by then-military law and as advised by most northern and western officers, rather, coup plotters were maintained in the military on full pay, and some were even promoted while awaiting trial. The coup, despite its failures, was seen by many as primarily benefiting the Igbo peoples, as the plotters received no repercussions for their actions and no significant Igbo political leaders were affected. While those that executed the coup were mostly Northern, most of the known plotters were Igbo and the military and political leadership of Western and Northern regions had been largely bloodily eliminated while the Eastern military/political leadership was largely untouched. However, Ironsi, himself an Igbo, was thought to have made numerous attempts to please Northerners. The other events that also fuelled suspicions of a so-called "Igbo conspiracy" were the killing of Northern leaders, and the killing of the Brigadier-General Ademulegun's pregnant wife by the coup executioners. Among the Igbo people, reaction to the coup was mixed.

Despite the overwhelming contradictions of the coup being executed by mostly Northern soldiers (such as John Atom Kpera, later military governor of Benue State), the killing of Igbo soldier Lieutenant-Colonel Arthur Unegbe by coup executioners, and Ironsi's termination of an Igbo-led coup, the ease by which Ironsi stopped the coup led to suspicion that the Igbo coup plotters planned all along to pave the way for Ironsi to take the reins of power in Nigeria.

Colonel Odumegwu Ojukwu became military governor of the Eastern Region at this time. On 24 May 1966, the military government issued Unification Decree #34, which would have replaced the federation with a more centralised system. The Northern bloc found this decree intolerable.

In the face of provocation from the Eastern media which repeatedly showed humiliating posters and cartoons of the slain northern politicians, on the night of 29 July 1966, northern soldiers at Abeokuta barracks mutinied, thus precipitating a counter-coup, which had already been in the planning stages. Ironsi was on a visit to Ibadan during their mutiny and there he was killed (along with his host, Adekunle Fajuyi). The counter-coup led to the installation of Lieutenant-Colonel Yakubu Gowon as Supreme Commander of the Nigerian Armed Forces. Gowon was chosen as a compromise candidate. He was a Northerner, a Christian, from a minority tribe, and had a good reputation within the army.

It seems that Gowon immediately faced not only a potential standoff with the East, but secession threats from the Northern and even the Western region. The counter-coup plotters had considered using the opportunity to withdraw from the federation themselves. Ambassadors from the United Kingdom and the United States, however, urged Gowon to maintain control over the whole country. Gowon followed this plan, repealing the Unification Decree, announcing a return to the federal system.