But, despite FW de Klerk's delight, there is another story doing the rounds: that, actually, Maggie played a blinder on the anti-apartheid team.
Take Richard Dowden, director of the Royal African Society, who wrote in the Guardian that Thatcher "played a pivotal role in the ending of apartheid in spite of herself".
Exhibit one is a letter she wrote to PW Botha in October 1985, reminding him of the potential positive effect of releasing Nelson Mandela. It is worth recalling, however, that Thatcher's last-in-the-queue call came nine months after Botha had offered Mandela conditional release and a decade after she became party leader.
Exhibit two is a meeting in June 1989 when she told De Klerk to get a move on with reaching a settlement. But, again, she was a Maggie-come-lately, a long way behind South Africa's business leaders, for example.
The spadework had been done by crippling financial sanctions, the boycott and disinvestment campaigns, and the township uprisings they fed off. De Klerk's room to manoeuvre was shrinking. Thatcher was doing no more than getting in line to service a fait accompli.
There's a third claim in her defence: that her hands were tied by Cold War realities. The argument goes that because the ANC was "communist-controlled", the West couldn't allow South Africa to fall into Soviet hands. And the corollary is that the fall of communism "freed" Thatcher et al to "permit" the transition to democracy – as if it was in their gift. As Daily Mail columnist Peter Hitchens put it: "Once it was clear that the Soviet menace was gone … Mrs Thatcher played a significant part in the release of Mandela and the peaceful handover of power."
Actually, the process of negotiation started in 1985 and the release of political prisoners began with Govan Mbeki in 1987, followed two years later by the rest of the Rivonia lifers, with the exception of Mandela – a month before the fall of the Berlin Wall and two years before the collapse of the Soviet Union. In other words, the concessions that enabled negotiations were made while the Cold War was still on the boil. Even Cold Warrior Thatcher, under considerable pressure, was prepared to implore Botha and harangue De Klerk while the Wall was still standing.
For then United States president Ronald Reagan and his assistant secretary of state, Chester Crocker, combating communism was paramount. Underpinning "constructive engagement" was the conviction that, when it came to a choice between apartheid and democracy, the devil they knew was preferable. Thatcher reached the same conclusion from a different angle, perhaps because her South African roots ran deeper. Her curmudgeonly husband, Denis, had an uncle who was a Durban businessperson, a factor the prompted his extensive South African investments.
In 1972 they sent their son, Mark, to Johannesburg for a year's work experience, and two years later they went on a tour of the country. One of their hosts was Botha, who pronounced himself highly impressed with Mrs Thatcher. There is no record of the Thatchers expressing moral misgivings about the apartheid they witnessed, but how much of this blinkered response was a product of racism?
Bob Carr, Australia's foreign minister, said he was astonished by Thatcher's racial outbursts when she visited in the 1990s. He said she warned him against Asian immigration, saying: "You'll end up like Fiji, where the Indian migrants have taken over."
Back in the 1970s, her views on South Africa were being moulded by the racist attitudes of her friend Laurens van der Post. In addition to being a Jungian mystic, a teller of tall tales about himself and a man who fathered a child with a 14-year-old, he believed in innate racial characteristics. Mandela's Xhosas were treacherous; Mangosuthu Buthelezi's Zulus were noble savages. Thatcher therefore did her best to champion the latter's cause.
It is said in her favour that although she might have lacked moral repugnance for apartheid she opposed it because it represented a barrier to a free market. This was also her argument for so resolutely opposing sanctions and disinvestment. Even when Britain was forced to follow the minimalist Commonwealth sanctions programme, she stressed that she had warded off a more stringent stance.
In 1984, Thatcher became the first British prime minister in 23 years to host an apartheid head of state. Three years later, she declared: "The ANC is a typical terrorist organisation." Her stance fostered a toxic ethos within her party. Thatcher's most loyal Cabinet colleague, Norman Tebbit, called Mandela a "terrorist". South Africa hosted regular apartheid-sponsored visits from Tory MPs, and Young Conservative leaders wore "Hang Nelson Mandela" badges.
Eventually, in 2006, Conservative leader David Cameron admitted they had got it wrong and that Mandela was "one of the greatest men alive". As part of his effort to detoxify the "nasty party", he added: "The fact that there is so much to celebrate in the new South Africa is not in spite of Mandela and the ANC, it is because of them – and we Conservatives should say so clearly."
Thatcher allies were outraged. But, for once, Cameron was right: her approach to apartheid was one of the more shameful dimensions of her legacy. For Botha and his generals, friends like Maggie gave cover for their harshest policies. They felt that their determination to crush opposition was part of a wider struggle against communism and that the big players in the West had their backs.
On the other hand, we saw how quickly the National Party's resolve crumbled when faced with crippling financial sanctions. If Thatcher had helped that to happen a decade earlier, the country could have been spared a great deal of brutality, the effects of which linger today.
Dr Gavin Evans teaches in the culture and media department, Birkbeck College, University of London. He worked for The Weekly Mail in the 1980s and 1990s