The key role played by the United States ahead of Zimbabwe's independence in resolving the sticky point of land redistribution has just come to light.
By Martin Plaut
BBC Africa analyst
The land issue has always been emotive in Zimbabwe - as can be seen with the current crisis sparked off by the government seizure of mainly white-owned farms in 2000.
And it was important to all parties in 1980 that signed the Lancaster House Agreement that led to the transformation of Rhodesia into Zimbabwe.
The road to the agreement was not straight forward, and as an investigation by the BBC's The Westminster Hour programme has revealed, it was much bumpier than at first suspected.
When former UK Prime Minister Margaret Thatcher came to power in 1979 the situation of Rhodesia had been a central concern of the British government for years.
A war had raged since the 1960s between the white government led by Ian Smith and liberation fighters led by Robert Mugabe and Joshua Nkomo.
Mrs Thatcher was persuaded - somewhat reluctantly - by her Foreign Secretary, Peter Carrington, to make one last push to try to resolve the issue.
"I didn't really think there was much prospect of success at Lancaster House because the sides were so far apart and in particular Smith had talked about it all for a thousand years and it was going to be a very difficult negotiation," Lord Carrington told the BBC.
"I didn't think it was going to work to be frank. I mean I thought it was going to end in tears."
But with the help of the then Commonwealth Secretary-General, Sir Shridath Ramphal, he managed to persuade all sides to attend.
Lengthy talks got under way in the splendour of Lancaster House, just opposite Buckingham Palace.
Gradually progress was made. Until the question of who would own the land.
It was the toughest of issues. Whites - 5% of the population - owned 80% of the arable land.
Millions of black people scratched a living on the rest.
For Mr Mugabe and Mr Nkomo this was critical.
Yet when Lord Carrington finally presented the draft constitution it contained no reference to the land.
White farmers owned 80% of the land before independence
Sir Shridath says the conference came close to collapse.
"From the British government's point of view the constitution was preserving the status quo for a minimum of 10 years," he says.
"When Nkomo and Mugabe saw it and understood the implications they blew up. They asked Carrington what he meant. The struggle was about land.
"Was he saying to them they must sign a constitution which says that they could not redistribute land because if that was the case they should go back to the bush and the conference broke up."
Sir Shridath believed the conference was doomed to failure and that Mr Mugabe and Mr Nkomo would walk out and the civil war would resume.
"I took an initiative of my own as secretary-general which isn't much known and talked about but can be now."
He secretly contacted the US ambassador in London, Kingman Brewster, and asked him to get the then US President, Jimmy Carter, to promise money to pay white farmers for their land.
Mr Mugabe was angered when the UK stopped land payments
"Brewster was totally supportive. We were at a stage where Mugabe and Nkomo were packing their bags," he explains.
"He came back to me within 24 hours. They had got hold of Jimmy Carter and Carter authorised Brewster to say to me that the United States would contribute a substantial amount for a process of land redistribution and they would undertake to encourage the British government to give similar assurances.
"That of course saved the conference."
Nearly 30 years after the Lancaster Conference, Lord Carrington was surprised to learn of Shridath Ramphal's secret intervention.
"Maybe that is so. Why should he pretend if it isn't true? But I didn't know anything about it at the time," he said.
For eight years the unwritten deal worked.
White farmers were paid around $35m by the UK for their land, which was then redistributed.
But the UK government found that some of the farms were being given to President Mugabe's close associates, and refused to continue the payments.
Mr Mugabe was furious, claiming bad faith.
The path to the seizure of white farms was opened and thus began the long slide to today's economic chaos.