Consequently, Gowon served for the longest continuous period as head of state of Nigeria, ruling for almost nine years until his overthrow in the coup d'état of 1975 by Brigadier Murtala Mohammed.

The then Lieutenant Colonel Gowon returned from his course at the Joint Staff College, Latimer UK two days before the coup – a late arrival that possibly exempted him from the plotters' hit list.

[16] Then came Aguyi Ironsi's Decree Number 34, which proposed the abolition of the federal system of government in favor of a unitary state, a position which had long been championed by some Southerners-especially by a major section of the Igbo-dominated National Council of Nigeria and the Cameroon (NCNC)[17] This was perhaps wrongly interpreted by Northerners as a Southern (particularly Igbo) attempt at a takeover of all levers of power in the country.

The original intention of Murtala Mohammed and his fellow coup-plotters was to engineer the secession of the Northern region from Nigeria as a whole, but they were subsequently dissuaded of their plans by several advisors, amongst which were a number of high-ranking civil servants and judges, and importantly emissaries of the British and American governments who had interests in the Nigerian polity.

[citation needed] The young officers then decided to name Lieutenant Colonel Gowon, who apparently had not been actively involved in events until that point, as Nigerian Head of State.

[2] Up until then, Gowon remained strictly a career soldier with no involvement whatsoever in politics, until the tumultuous events of the year suddenly thrust him into a leadership role, when his unusual background as a Northerner who was neither of Hausa nor Fulani ancestry nor of the Islamic faith made him a particularly safe choice to lead a nation whose population was seething with ethnic tension.

The oil-price boom, which began as a result of the high price of crude oil (the country's major revenue earner) in the world market in 1973, increased the federal government's ability to undertake these tasks.

It has been said without confirmation that both Gowon and Ojukwu had knowledge of the huge oil reserves in the Niger Delta area, which today has grown to be the mainstay of the Nigerian economy.

[26] The flight of many of them back to their villages in the "Igbo heartland" in Eastern Nigeria where they felt safer was alleged to be a contradiction for Gowon's "no victor, no vanquished" policy, when at the end of the war, the properties they left behind were claimed by the Rivers State indigenes.

[27] Towards the end of July 1967, Nigerian federal troops and marines captured Bonny Island in the Niger Delta, thereby taking control of vital Shell-BP facilities.

[30] This was to trigger a war that would last some 30 months, and see the deaths of more than 100,000 federal soldiers and three million Biafran combatants and civilians, most of the latter of which perished through starvation under a Nigerian-imposed blockade.

Gowon subsequently made his famous "no victor, no vanquished" speech, and followed it up with an amnesty for the majority of those who had participated in the Biafran uprising, as well as a program of "Reconciliation, Reconstruction, and Rehabilitation",[35][36] to repair the extensive damage done to the economy and infrastructure of the Eastern Region during the years of war.

[41] The post-civil-war years saw Nigeria enjoying a meteoric, oil-fuelled, economic upturn in the course of which the scope of activity of the Nigerian federal government grew to an unprecedented degree, with increased earnings from oil revenues.

[42] On 1 October 1974, in flagrant contradiction to his earlier promises, Gowon declared that Nigeria would not be ready for civilian rule by 1976, and he announced that the handover date would be postponed indefinitely.

Its attempts to repudiate the cement contracts and impose an emergency embargo on all inbound shipping tied up the country in litigation around the world for many years, including a 1983 decision of the U.S. Supreme Court.

On 29 July 1975, while Gowon was attending an OAU summit in Kampala, a group of officers led by Colonel Joe Nanven Garba announced his overthrow.

[27] In February 1976, Murtala Mohammed was assassinated in an unsuccessful coup d'état led by Lt. Col Buka Suka Dimka, who implicated Gowon.

As a result of the coup tribunal findings, Gowon was declared wanted by the Nigerian government, stripped of his rank in absentia, and had his pension cut off.

[52] In November 2020, MP Tom Tugendhat, while speaking against the Nigerian government's repression of the 2020 #EndSARS mass protests, accused Gowon of looting "half of the Central Bank of Nigeria" after his overthrow in the coup d'état of 1975.

[53] The statement, the first-ever attempt to link Gowon with corruption, was faced with considerable backlash within Nigeria,[54] with Bishop Matthew Kukah writing in the national major Daily Trust describing the seemingly ridiculous comment as "It is difficult to understand how a Member of the revered British Parliament worth his salt, could have left himself open to ridicule by leveling the unfounded, irrational and bizarre allegations of corruption against General Yakubu Gowon, our former Head of State and to the hilt, the nation's poster face of probity in public life."

[56] Gowon married Victoria Zakari, a trained nurse in 1969 at a ceremony officiated by Seth Irunsewe Kale at the Cathedral Church of Christ, Lagos.