Was Idi Amin a buffoonish brute – or a cunning political operator?

Forty years after his downfall, General Idi Amin remains high on the list of Africa’s most notorious dictators. His record as president of Uganda, after seizing power in 1971, includes mass killings, chaotic administration, economic collapse and the murder of scores of prominent Ugandans, including the chief justice and an archbishop. In the West, Amin is still a byword for brutality and buffoonery.

His interventions on the world stage were bizarre. He frequently fired off provocative messages to Western leaders in the hope of gaining credit in African circles as a fearless champion of the anti-colonial cause. He wished US president Richard Nixon “a speedy recovery from Watergate”, and offered Britain’s music-loving prime minister, Edward Heath, the post of bandmaster after his election defeat.

He also sent a long telegram to Queen Elizabeth proposing he should visit Britain in 1975. “It is ardently hoped and expected that you will, through various agencies, arrange for me so I can see and visit Scotland, Wales and Northern -Ireland. I should like that chance to talk to these people who are struggling for self-determination and independence…” He claimed to be “the true heir to the throne of Scotland”, and delighted in awarding himself military medals and grandiose titles, such as “Conqueror of the British Empire’”. In much of Africa, he was regarded as something of a hero. His appearances at annual meetings of the Organisation of African Unity, weighed down with medals and gold braid, inspired enthusiastic applause.

A miasma of rumour, gossip and fabrication soon built up around him. He is said to have enjoyed eating human flesh; to have kept human heads in the fridge; to have engaged in blood rituals; to have had his wives murdered. Some stories came from Amin himself, boasts and exaggerations of his prowess told for dramatic effect.

Mark Leopold, a British anthropologist, first became interested in Amin when carrying out ethnographic research in the 1990s in Amin’s home district in the West Nile, a remote corner of north-western Uganda. “I found that his presence haunted the place, and his deeds hung over its population as a permanent cloud,” he writes. “He came to haunt me, too.”

In his new book, Leopold has undertaken the task of trying to sift fact from fiction. He quotes extensively from a wide range of conflicting accounts of Amin’s character, origins and career, testing their reliability. He has also made extensive use of Britain’s National Archives, trawling through the dispatches of diplomats and officials who had dealings with Amin.

Amin’s life was largely shaped by his connections to Britain’s colonial forces. His father, a Muslim Kakwa from the West Nile, served in both the King’s African Rifles (KAR) and in the police. When Amin himself joined the KAR at about the age of 18, he was virtually illiterate, with only a rudimentary education and a poor grasp of English, but he gained attention by excelling at sport and marksmanship and by deploying qualities of stamina and loyalty, which British officers admired. A man of huge physique, he became a national heavyweight boxing champion.

During the 1950s, he made steady progress up the ranks. Promoted to corporal, he served with KAR units sent to Kenya to help suppress the Mau Mau insurrection. British officers praised him as a “first-class platoon commander”. In 1959 he reached the rank of warrant officer, the highest position then open to African soldiers. But despite his leadership ability, he was not regarded as “officer material”. Sent on special army education courses, Amin made little headway.

However, in the rush to find suitable African officers before Uganda’s independence in 1962, Amin was promoted to lieutenant in 1961 and captain the following year, one of only two African officers serving in the Ugandan army at the time.

Amin’s progress after independence was even more remarkable. Uganda’s prime minister, Milton Obote, a left-wing intellectual, trusted him as a bluff, loyal and simple soldier who would do his bidding without too much scruple and gave him command of his own battalion. When Obote made a power grab in 1966, setting Uganda on the road to dictatorship, he relied on Amin to smash resistance from the Buganda monarchy. Amin was duly rewarded with promotion to brigadier and army commander.

Henceforth, Obote depended on Amin to back up his dictatorship. But they soon became rivals, splitting loyalties within the army. When Obote made an ill-considered attempt to seize control of the army in 1971, Amin struck back.

Amin’s coup was widely welcomed by many Ugandans and also by the British government, which had endured a fractious time with Obote. Among other disputes, Obote had made clear his intention of expelling Asian residents holding British passports, a wealthy and unpopular immigrant minority. Amin was invited to Britain in July 1971, given a sumptuous dinner at Number 10, Downing Street, followed by a lunch with the Queen at Buckingham Palace and a tour of Scotland for which he had formed a particular liking.

But the following year, as capricious as ever, he fell out with the British government and ended up expelling the Asian community, as Obote had wanted to do. By then, as he struggled to maintain control, the surge of mass killings, murders and mayhem was well under way. Amin survived in power for eight years, before fleeing into exile in 1979, as the remnants of his army disintegrated.

Leopold gives a far more nuanced version of Amin than the common picture of him as a psychotic monster. He portrays him not as a simpleton, as he sometimes liked to present himself, but as a man of considerable intelligence and cunning, with an eye to the main chance. Leopold concedes that so much of Amin’s story has become embedded in myth and fabrication that separating fact from fiction became “an impossible task”. Nevertheless, he concludes that Amin did not have his wives murdered, nor was he a cannibal, nor did he keep human heads in the fridge.

Martin Meredith is the author of The State of Africa. His latest book, Zimbabwe: Myth, War and Tragedy, is published by Simon & Schuster on April 29

Idi Amin by Mark Leopold is published by Yale at ￡35. To order your copy for ￡30, call 0844 871 1514 or visit Telegraph Books