President Mugabe began murdering his opponents less than three years after he came to power in 1980, declaring that his rule would mark “the age of love” and reconciliation with the Rhodesian whites against whom he had fought.

A low-level insurgency that began in 1982 with disaffected former guerrillas of the Ndebele-based Zimbabwe People's Revolutionary Army (Zipra), who had fought alongside Mr Mugabe in the civil war, received a savage response.

Led by soldiers of the 5 Brigade of the Zimbabwe National Army, who were trained in North Korea, a campaign of systematic massacre was carried out against the rural people of Matabeleland, whom Mr Mugabe regarded as providing shelter, food and intelligence for the ex-Zipra “dissidents”. Soldiers, covert operations police and intelligence agents wiped out entire villages, by bullet or bayonet, or carted them off to camps where they were murdered, usually after being tortured.

The violence came to an end in 1988 after Mr Mugabe negotiated with the Ndebele leader, Joshua Nkomo, his former comrade-in-arms, and his Zapu party, and absorbed them into Zanu (PF).

The organised massacre was largely ignored by Western embassies in Harare. When the Zimbabwe Catholic Bishops' Conference protested, Mr Mugabe derided them as “sanctimonious prelates”. A relatively small number of journalists brought it to international attention but Mr Mugabe was unscathed, able to dismiss it as “a moment of madness”.

Nine years later the Legal Resources Foundation (LRF) and the Catholic Commission for Justice and Peace in Zimbabwe (CCJP) delivered a 260-page report on their investigations into what Mr Mugabe called Operation Gukurahundi (“the rain that washes away the chaff”). Interviewing thousands of survivors and victims' relatives, the report, Breaking the Silence, pieced together the atrocities in detail, although there were huge gaps in the information because so many of the witnesses had been murdered. The report was able to identify 1,791 victims. It said that “the figure is reasonably certainly 3,750 dead. More than that it is not possible to say, except to allow that the real figure for the dead could be double 3,000, or even higher.”

Further research was carried out by human rights researchers in Matabeleland. The climate of fear that still pervaded while the CCJP and the LRF carried out their investigations had abated considerably. Villagers were less frightened to take researchers to the sites of mass graves in the bush, or to the bottoms of mine shafts, and felt free to speak. Reports have yet to be published but, said one of the researchers who asked not to be named, “the final tally is no fewer than 10,000 and no more than 20,000”.

Relative calm persisted through to 2000, when Mr Mugabe found his continued rule suddenly undermined by a new political party engendered by the growth of democracy that came with the collapse of the Soviet bloc.

The loss of a referendum shocked Mr Mugabe into action. Within two weeks, lawless “war veterans” were invading white-owned commercial farms and attacking the six-month-old Movement for Democratic Change (MDC).

On the same day in mid-April, a war veteran and an officer of Mr Mugabe's Central Intelligence Organisation firebombed Morgan Tsvangirai's driver, Tichaona Chiminya, and an aide, Talent Mabika, burning them alive in the cab of the pick-up lorry that they were in, while another group abducted the farmer David Stevens - an MDC support worker, like many other young white farmers. He was beaten and shot in the back of the head.

“By the time 2000 and the MDC came round, Mugabe and the Joint Operational Command realised that massacres were politically unviable, so they adopted a strategy of focused killings and torture,” said a human rights researcher who asked not to be named. “That way everybody gets the message.”

After the defeat of Zanu (PF) in parliamentary elections on March 29 and a narrow loss in the presidential vote that called for a second round, Mr Mugabe and the Joint Operational Command cast restraint to the wind. The death toll now stands at 85 in less than 12 weeks - about one killing a day - a figure far worse than anything since 2000, while the torture is so intense that doctors have stated that they have been overwhelmed.

“There are more who were buried without being taken to a hospital, others who were dumped and their bodies have not been found, and those who crept off to escape, but died of their injuries,” said a doctor who asked not to be named.

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