The first time Emmanuel Ifeajuna appeared before a crowd of thousands he did something no black African had ever done. He won a gold medal at an international sporting event. “Nigeria Creates World Sensation,” ran the headline in the West African Pilot after Ifeajuna’s record-breaking victory in the high jump at the 1954 Empire and Commonwealth Games in Vancouver. He was the pride not just of Nigeria but of a whole continent. An editorial asked: “Who among our people did not weep for sheer joy when Nigeria came uppermost, beating all whites and blacks together?”

In the words of a former schoolmate, Ifeajuna had leaped “to the very pinnacle of Nigerian sporting achievement”. His nine track and field team-mates won another six silver and bronze medals, prompting a special correspondent to write “Rejoice with me, oh ye sports lovers of Nigeria, for the remarkable achievements of our boys”.

Ifeajuna, feted wherever he went, would soon see his picture on the front of school exercise books. He was a great national hero who would remain Nigeria’s only gold medallist, in Commonwealth or Olympic sport, until 1966.

The next time Ifeajuna appeared before a crowd of thousands he was bare-chested and tied to a stake, facing execution before a seething mob. He had co-led a military coup in January 1966 in which, according to an official but disputed police report, he shot and killed Nigeria’s first prime minister. The coup failed but Ifeajuna escaped to safety in Ghana, dressed as a woman and was driven to freedom by a famous poet. Twenty months later, he was back, fighting for the persecuted Igbo people of eastern Nigeria in a brutal civil war that broke out as a consequence of the coup.

Ifeajuna and three fellow officers were accused by their own leader, General Emeka Ojukwu, of plotting against him and the breakaway Republic of Biafra. They denied charges of treason: they were trying to save lives and their country, they said, by negotiating an early ceasefire with the federal government and reuniting Nigeria. They failed, they died and, in the next two and a half years, so did more than a million Igbos.

The day of the execution was 25 September, 1967, and the time 1.30pm. There was a very short gap between trial and execution, not least because federal troops were closing in on Enugu, the Biafran capital, giving rise to fears that the “guilty four” might be rescued.

As the execution approached, the four men – Ifeajuna, Victor Banjo, Phillip Alale and Sam Agbam – were tied to stakes. Ifeajuna, with his head on his chest as though he was already dead, kept mumbling that his death would not stop what he had feared most, that federal troops would enter Enugu, and the only way to stop this was for those about to kill him to ask for a ceasefire.

A body of soldiers drew up with their automatic rifles at the ready. On the order of their officer, they levelled their guns at the bared chests of the four men. As a hysterical mass behind the firing squad shouted: “Shoot them! Shoot them!” a grim-looking officer gave the command: “Fire!” The deafening volley was followed by lolling heads. Ifeajuna slumped. Nigeria’s great sporting hero died a villain’s death. But he had been right. By 4pm two and a half hours after the executions, the gunners of the federal troops had started to hit their targets in Enugu with great accuracy. The Biafrans began to flee and the city fell a few days later.

Of all the many hundreds of gold medallists at the Empire and Commonwealth Games since 1930 none left such a mark on history, led such a remarkable life or suffered such a shocking death as Ifeajuna.

His co-plotter in the 1966 coup, Chukwuma Nzeogwu, was buried with full military honours and had a statue erected in his memory in his home town. But for Ifeajuna, the hateful verdict of that seething mob carried weight down the years. His name was reviled, his sporting glory all but written out of Nigeria’s history. His name is absent from the website of the Athletics Federation of Nigeria, appearing neither in the history of the Federation nor in any other section. There is no easy road to redemption for the gold medallist who inadvertently started a war and was shot for trying to stop it.

Nigeria’s first foray into overseas sport was in 1948, when they sent athletes to London to compete in the Amateur Athletic Association Championships, and to watch the Olympic Games before a planned first entry in the next Olympiad. In 1950 there was cause to celebrate when the high jumper, Josiah Majekodunmi, won a silver medal at the Auckland Commonwealth Games. He also fared best of Nigeria’s Olympic pathfinders, the nine-man team who competed at Helsinki in 1952. Majekodunmi was ninth, with two of his team-mates also in the top 20. Nigerians clearly excelled at the high jump.

With three men having competed in that 1952 Olympic final, the Nigeria selectors had plenty of names to consider for the Commonwealth Games high jump in Vancouver two years later. Ifeajuna, aged 20, was not a contender until he surprised everybody at the national championships in late April, less than two months before the team were due to depart. His jump of 6ft 5.5in, the best of the season, took him straight in alongside Nafiu Osagie, one of the 1952 Olympians, and he was selected.

The high jump was on day one of competition in Vancouver and Ifeajuna wore only one shoe, on his left foot. One correspondent wrote: “The Nigerian made his cat-like approach from the left-hand side. In his take-off stride his leading leg was flexed to an angle quite beyond anything ever seen but he retrieved position with a fantastic spring and soared upwards as if plucked by some external agency.”

Ifeajuna brushed the bar at 6ft 7in but it stayed on; he then cleared 6ft 8in to set a Games and British Empire record, and to become the first man ever to jump 13.5in more than his own height. This first gold for black Africa was a world-class performance. His 6ft 8in – just over 2.03m – would have been good enough for a silver medal at the Helsinki Olympics two years earlier.

The team arrived back home on 8 September. That afternoon they were driven on an open-backed lorry through the streets of Lagos, with the police band on board, to a civic reception at the racecourse. The flags and bunting were out in abundance, as were the crowds in the middle and, for those who could afford tickets, the grandstand. There was a celebration dance at 9pm. Ifeajuna told reporters he had been so tired, having spent nearly four hours in competition, that: “At the time I attempted the record jump I did not think I had enough strength to achieve the success which was mine. I was very happy when I went over the bar on my second attempt.”

After a couple of weeks at home Ifeajuna was off to university on the other side of the country at Ibadan. His sporting career was already over, apart from rare appearances in inter-varsity matches. He met his future wife, Rose, in 1955. They married in 1959 and had two sons. After graduating in zoology he taught for a while before joining the army in 1960 and was trained in England, at Aldershot. Ifeajuna had first shown an interest in the military in 1956 when, during a summer holiday in Abeokuta, he had visited the local barracks with a friend who later became one of the most important figures in the Commonwealth.

Chief Emeka Anyaoku joined the Commonwealth Secretariat in 1966, the year of Ifeajuna’s coup attempt. While his good friend escaped, returned, fought in the war and died in front of the firing squad, Anyaoku moved to London, where he rose to the highest office in the Commonwealth, secretary-general, in 1990. For four years at university he lived in a room next door to Ifeajuna, who became a close friend.

Why did the record-breaking champion stop competing? “From October, 1954, when he enrolled at Ibadan, he never trained,” said Anyaoku, nearly 60 years later. “He never had a coach – only his games master at grammar school – and there were no facilities at the university. He simply stopped. He seemed content with celebrating his gold medal. I don’t think the Olympics ever tempted him. I used to tease him that he was the most natural hero in sport. He did no special training. He was so gifted, he just did it all himself. Jumping barefoot, or with one shoe, was not unusual where we came from.”

Another hugely influential voice from Nigerian history pointed out that Ifeajuna, in his days as a student, had “a fairly good record of rebellion”. Olusegun Obasanjo served as head of a military regime and as an elected president. He recalled Ifeajuna’s role in a protest that led to the closure of his grammar school in Onitsha for a term in 1951, when he was 16. Three years after winning gold, while at university, Ifeajuna made a rousing speech before leading several hundred students in protest against poor food and conditions.

The former president also held a manuscript written by Ifeajuna in the aftermath of the coup but never published. It stated: “It was unity we wanted, not rebellion. We had watched our leaders rape our country. The country was so diseased that bold reforms were badly needed to settle social, moral, economic and political questions. We fully realised that to be caught planning, let alone acting, on our lines, was high treason. And the penalty for high treason is death.”

In 1964 the Lagos boxer Omo Oloja won a light-middleweight bronze in Tokyo, thereby becoming Nigeria’s first Olympic medallist. It was a rare moment of celebration in a grim year that featured a general strike and a rigged election. Another election the following year was, said the BBC and Reuters correspondent Frederick Forsyth, seriously rigged – “electoral officers disappeared, ballot papers vanished from police custody, candidates were detained, polling agents were murdered”. Two opposing sides both claimed victory, leading to a complete breakdown of law and order. “Rioting, murder, looting, arson and mayhem were rife,” said Forsyth. The prime minister, Tafawa Balewa, refused to declare a state of emergency. There was corruption in the army, too, with favouritism for northern recruits. A group of officers began to talk about a coup after they were told by their brigadier that they would be required to pledge allegiance to the prime minister, from the north, rather than the country’s first president, an Igbo. Ifeajuna’s group feared a jihad against the mainly Christian south, led by the north’s Muslim figurehead, the Sardauna of Sokoto.

The coup, codenamed Leopard, was planned in secret meetings. Major Ifeajuna led a small group in Lagos, whose main targets were the prime minister, the army’s commander-in-chief, and a brigadier, who was Ifeajuna’s first victim. According to the official police report, part of which has never been made public, Ifeajuna and a few of his men broke into the prime minister’s home, kicked down his bedroom door and led out Balewa in his white robe. They allowed him to say his prayers and drove him away in Ifeajuna’s car. On the road to Abeokuta they stopped, Ifeajuna ordered the prime minister out of the car, shot him, and left his body in the bush. Others say the Prime Minister was not shot, nor was the intention ever to kill him: Balewa died of an asthma attack or a heart attack brought on by fear. There has never been conclusive evidence either way.

Ifeajuna drove on to Enugu, where it became apparent that the coup had failed, mainly because one of the key officers in Ifeajuna’s Lagos operation had “turned traitor” and had failed to arrive as planned with armoured cars. Major-General Ironsi, the main military target, was still at large and he soon took control of the military government. Ifeajuna was now a wanted man. He hid in a chemist’s shop, disguised himself as a woman, and was driven over the border by his friend Christopher Okigbo, a poet of great renown. Then he travelled on to Ghana, where he was welcomed.

Ifeajuna eventually agreed to return to Lagos, where he was held pending trial. Ojukwu, by now a senior officer, ensured his safety by having him transferred, in April, to a jail in the east. Igbos who lived in the north of the country were attacked. In weeks of violent bloodshed tens of thousands died. As the death toll increased, the outcome was civil war. In May, 1967, Ojukwu, military governor of the south-east of Nigeria, declared that the region had now become the Republic of Biafra. By the time the fighting ended in early 1970, the number of deaths would be in the millions.

Arguably, if either of Ifeajuna’s plots had been a success, those lives would not have been lost. The verdicts on his role in Nigerian history are many and varied: his detractors have held sway. Chief among them was Bernard Odogwu, Biafra’s head of intelligence, who branded Ifeajuna a traitor and blamed him for “failure and atrocities” in the 1966 coup. Adewale Ademoyega, one of the 1966 plotters, held a different view of Ifeajuna. “He was a rather complicated character ... intensely political and revolutionary ... very influential among those close to him ... generous and willing to sacrifice anything for the revolution.”

The last time Anyaoku saw Ifeajuna was in 1963, in Lagos, before Anyaoku’s departure for a diplomatic role in New York. He later moved to London and was there in 1967. “I was devastated when I heard the news of the execution,” he said. As for Ifeajuna being all but written out of Nigeria’s sporting history, he noted that: “The history of the civil war still evokes a two-sided argument. He is a hero to many people, though they would more readily talk about his gold medal than his involvement in the war. There are people who think he was unjustifiably executed and others who believe the opposite.”

One commentator suggested recently that the new national stadium in Abuja, the Nigerian capital, should be named after Ifeajuna. It will surely never happen.

•Courtesy of the Observer, London. This is an edited extract from the book, “The Commonwealth Games: Extraordinary Stories Behind The Medals”, by Brian Oliver, a former sports editor of the Observer, published by Bloomsbury. Photo shows the late Ifeajuna.

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