Successive British governments have accused Zimbabwe's President Robert Mugabe of brutal, corrupt and incompetent rule, but new evidence suggests that without British help, he might not have lived long enough to come to power.
In the late 1970s, Mugabe and fellow leader of the Patriotic Front Joshua Nkomo were waging war against Ian Smith's white minority government in what was then Rhodesia.
Mugabe, backed by the Chinese, based his Zimbabwe African National Union (Zanu) forces across the border in Mozambique, while Nkomo's Zimbabwe African People's Union (Zapu) were camped in neighbouring Zambia.
Smith's government had declared unilateral independence (or UDI) from Britain in 1965, and so London watched from the sidelines as the vicious conflict unfolded during the late 1970s.
On 3 September 1978, the conflict took a turn that outraged even war-weary Rhodesia.
Nkomo's forces shot down a civilian jet carrying 56 passengers.
Ten of the survivors, who included women and children, were then butchered on the ground.
Five months later, his men shot down another civilian plane killing all 59 on board.
White Rhodesia demanded revenge.
On Good Friday 1979, a column of Rhodesian SAS soldiers crossed into northern Zambia, bound for the country's capital, Lusaka. Their mission - codenamed Operation Bastille - was to assassinate Joshua Nkomo.
This audacious attack was witnessed by Britain's deputy high commissioner in Lusaka, Mark Chapman.
In a telegram he said, "At 03:00 hours heavy machine gunfire broke out, punctuated by explosions. It lasted about 15 minutes and Nkomo's house was set ablaze".
But Nkomo had escaped.
Rhodesian special forces were stunned. Suspicions soon turned to the possibility that he had been tipped off.
But, they wondered, who within their ranks would have passed on such information?
'Pretty clear link'
It was widely suspected that the British had somehow got wind of the raid and warned Nkomo's men.
New evidence seen by the BBC's Document programme, suggests they might have been right.
Just a few days after the failed raid, this confidential note was written by then foreign secretary David Owen's political adviser David Stephen, to the Rhodesia Department of the Foreign and Commonwealth Office:
"Dr Owen told me this morning that he has been considering how to respond to Mr Nkomo's request that Dr Owen's request to Mr Nkomo should be made public. Dr Owen sees difficulties in such a course of action."
So what message had Dr - now Lord - Owen, sent to Nkomo? More than 30 years later, this was his answer:
"I think it was connected to whether or not we had tipped him off about an assassination attempt. It seems to be a pretty sensible thing, a pretty clear link."
As to how the British government could have come by information about such planned assassinations by the Rhodesians, Lord Owen can clear up that mystery too.
"The head of Rhodesian Intelligence, Ken Flowers, was also on our side. So I was well aware of what Ken Flowers was claiming was being done, and I used to read the reports."
The British government, which was opposed to Ian Smith's white minority government, was working hard to find a peaceful end to the war.
London believed this could only come about if rebel leaders Joshua Nkomo and Robert Mugabe were part of any solution.
So the Foreign Office was desperate to ensure that both men would make it to the Lancaster House peace talks that were due to take place in London later that year.
'Mugabe was called'
This might explain why British officials kept in regular touch with both Nkomo and Mugabe.
Lord Robin Renwick was then a member of the Foreign Office team working on the Rhodesian conflict.
"We did at the time have a colleague in Lusaka who was in almost daily contact with Nkomo, and a colleague in Mozambique who was in daily contact with Zanu leadership too," he said.
Peter Petter-Bowyer, a senior figure at Rhodesian Military Headquarters at the time, believes Britain also helped foil one of several attempts on Robert Mugabe's life.
It took place, he said, with the help of the South African Navy at Mugabe's base in the Mozambique capital, Maputo.
"We had absolute proof. The guy who lived across the road from Mugabe, he happened to be a South African, I met the man, confirmed that Mugabe was at home and all was well.
"But, when we got there, [he had] gone. No question, Mugabe was called, there's no doubt. That's exactly what happened."
I asked Mr Petter-Bowyer who he believes called Mugabe.
"The Brits," he replied firmly.
The confidential memo below, sent to the British Embassy in Maputo, shows how closely Mugabe's forces there were being monitored by London:
"In view of Mozambique's importance as one of the front-line states with respect to Rhodesia, and of the presence of the Zanu (Mugabe) headquarters in Maputo, the Embassy is called on to provide constant reporting on the activities of Zanu and the Mozambican attitude to Rhodesia."
In the end, both Robert Mugabe and Joshua Nkomo survived the various attempts on their lives and made it to London for the Lancaster House talks which proved successful.
Mugabe won the elections that followed and decades later is still in power.
During his time in office, he has virtually bankrupted his country and killed, beaten or jailed tens of thousands of his people.
Britain took pride in opposing his assassination.
With the benefit of hindsight, was this one occasion when London should have abandoned normal rules and simply turned a blind eye?
Despite what has happened since, Lord Owen is still convinced that what Britain did was right.
"I think assassination was not the route to peace. Mugabe was at that time, I think, the genuine choice of the Rhodesian people.
"What went wrong? If we could have avoided Mugabe being the top man, then the history of Zimbabwe would have been a great deal better one.
"The 'ifs' of history."