Last Christmas, the recently widowed Baroness Thatcher enjoyed an afternoon in the company of her son and some of his friends by the sun-drenched pool of his luxury home in Cape Town.
Among them was a certain Simon Mann, and several other former crack soldiers known to Sir Mark. The Iron Lady could have had no idea that months later, some of those present would be desperately denying involvement in a mercenaries' plot to overthrow the dictatorship of President Teodoro Obiang of Equatorial Guinea.
Sir Mark himself faces questioning regarding his alleged role. A hearing scheduled for today has been postponed for two weeks. The wait goes on.
But a year ago it was all so different. He and Mann were among the elite of South African society, luxuriating in the tree-lined avenues and gardens where as much fine wine sloshed around as there was water in swimming polls. They had bought into a lifestyle. They had found Constantia.
Since the demise of apartheid made South Africa fashionable, those lured to Cape Town by the weather, the wine, the mountains and the ocean - not to mention a cheap exchange rate - have wanted to live in one place: Constantia. But they had to have money.
"What we have here is unique," said a long-time resident as we sat by his pool, and it was easy to see what he meant. Sheltered from the south-easterly gales which batter the rest of the Cape Peninsula, sycamores, planes and centuries-old oaks soar to the azure sky. All the tracks found on the earliest maps have been preserved as bridle paths, which wind across the valley untainted by any motor traffic.
Subdivision of properties is banned; in High Constantia, where the minimum plot size is two acres, millionaires' mansions form a contour line of their own, with mountains behind and False Bay in the distance. It is as though Beverly Hills has been transplanted to San Francisco.
When the likes of Hugh Grant or Richard Branson are in town, this is where they are to be found. It is just a pity that so many of the expatriate crowd who settle here seem to be getting away from something.
"You can buy a superb lifestyle here," said the previously mentioned resident. (Like everyone else I spoke to in this Nirvana, he did not want to be quoted by name.) "Cape Town does not produce much wealth - all the minerals and the big financial deals are up north - but this is where they come to spend their money."
The secret was long known to some in international high society, but it began to leak out when Earl Spencer moved here in 1993, just before South Africa's first free election, and his royal sister was seen around Constantia. By the time Mark Thatcher (as he was then) arrived two years later, the rush was on. European and American expatriates joined in, buying up languishing wine estates such as Buitenverwachting and Steenberg and transforming them into luxury hotel and golf complexes which just happened to produce fine wine as well.
It did not always do to ask where the money came from. One of the biggest German property buyers in Constantia is in jail back in his native land. And African dictators have turned up to buy mansions with suitcases full of cash. Bizarrely, Sir Mark's stunning home has as neighbours properties owned by none other than President Obiang and several other members of the Obiang clan.
The old inhabitants of the Constantia Valley watched with a mixture of delight at the surging value of their houses, and horror at the brashness of some of the newcomers. ("That's the thing about this place," said one of them. "We seem to attract all the bad boys.")
For Constantia has a long and rich history. It first became renowned in Britain for its wine. The exiled Napoleon Bonaparte on St Helena had a love of the sweet produce of the vineyards tucked away behind Table Mountain. Vin de Constance did not maintain its pre-eminence for long, however.
English tastes moved to sherry and Marsala, which could be shipped in quantity over shorter sea routes, and by the 1870s Constantia's fame had ebbed. Eventually, the South African government had to take over Groot Constantia, the oldest vineyard in the southern hemisphere, and turn it into a national museum to stop it going down market or closing.
That has contributed, however, to the sylvan atmosphere which has again given Constantia name-recognition in Britain and made it one of the most desirable places to live on earth, attracting a new wave of wealthy residents.
There was no doubt how Pam Golding, one of Cape Town's leading estate agents, felt about the influx of new residents. Shortly after she sold Sir Mark his 15,000 sq ft house, she gushed: "Yes, Constantia is a very prestigious address for him. We have all sorts of foreign investors acquiring at the moment. The most popular ones are what I call the gentleman's country estate, with glorious manor houses and villas. It's really a millionaire's pride and joy."
But, despite the unstinted admiration of many Constantia-ites for his mother, Mark did not gain automatic acceptance in local society. "We weren't impressed," said a guest at a dinner party Ms Golding gave for the new arrival. "What really left a sour taste was his boasting about living the grand life in Cape Town and not having to pay any tax. It was a very silly thing to say in front of complete strangers who did have to pay their taxes." Other rebuffs followed, most notoriously his failure to gain membership of the Royal Cape Golf Club.
After a scheme to make loans to Cape Town policemen collapsed amid rancour in 1998, his less-than-glorious past began to be raked up - how he had left Harrow with three O-levels, failed his accountancy exams three times, got lost in the Sahara, and decamped to Texas following complaints about commissions gained in the Middle East while his mother was prime minister.
Amid all the gleeful bitchiness - it was rumoured that he had first come to the Cape when his mother sent him here as a teenager to clear his spots, which had allegedly earned him the nickname "Scratcher" at Harrow - perhaps it is not surprising that he began to look around for new friends. If one "Constantia set" rejected him, he found another: men who, like him, were happier talking about aircraft and fast cars than world politics or the kind of Third World poverty you can observe in Cape Town, if you emerge from the Constantia cocoon.
Though he carries himself with a ramrod military bearing, Sir Mark has never been in the army. But most of his new friends had, notably the one to whom he seems to have been closest. It is easy to imagine that the former prime minister's socially inept son found much to admire in Simon Mann, an old Etonian his own age - they are both in their early 50s - who served in the Guards and the SAS before making a fortune in Africa with Executive Outcomes, the first of the private military companies which have proliferated in the world's trouble spots. With his wealth he acquired a property in Constantia and an estate in Hampshire.
During poolside barbecues Sir Mark met Mr Mann's friend David Tremain, an Anglo-South African and fellow Constantia resident who, like Sir Mark, was engaged in dealmaking around Africa. There were also former members of South Africa's apartheid-era special forces who supplied the bulk of Executive Outcomes' muscle, such as Nick du Toit and Crause Steyl.
Mr Mann was arrested at Harare airport in Zimbabwe with a cache of arms. He had just met an aircraft which had arrived from Pretoria with more than 60 former members of South Africa's special forces aboard. All were jailed for up to a year on immigration charges, while Mr Mann is serving seven years for illegal arms buying. Mr du Toit, seven other South Africans and six Armenian aircrew are on trial in Malabo, the capital of Equatorial Guinea, where they are due to hear the verdicts today.
David Tremain, meanwhile, is said to have been on a light aicraft, flown by Crause Steyl, which was flying to Equatorial Guinea. They reached Mali before they learned that the coup had collapsed, and turned back. Mr Tremain denies the allegations, but has not deemed it prudent to return to South Africa to contest them.
Sir Mark, whose circle had left Constantia, was preparing to leave himself. Under pressure from Diane to return to Texas, he put the mansion on the market for just under £2m - though not with Pam Golding, locals have noticed. But on 25 August, just a day before he was due to depart, he was arrested.
In the torrent of leaks, allegations and off-the-record briefings which has poured out since, Ely Calil, a Lebanese-born oil trader based in London, has been named as the mastermind of the plot, which he denies. His friend, Lord Archer of Weston-super-Mare, has denied being the "JH Archer" listed as transferring money to one of Mr Mann's companies just before the attempted coup. And Sir Mark has denied being the "Scratcher" named in an intercepted note smuggled from prison by Mr Mann.
All the allegations will eventually be tested in court, but when and where remains uncertain. In the meantime, Equatorial Guinea is enjoying its moment in the spotlight, launching court actions in Britain against alleged coup backers and in South Africa to question Sir Mark. It has also charged him in absentia, and is talking of seeking extradition.
The South African authorities, determined to show that they no longer tolerate mercenary activity, have charged him under the Foreign Military Assistance Act. On Wednesday, Sir Mark lost a court bid to stop Equatorial Guinea asking him questions, and is due to return today to answer them. In a two-minute hearing yesterday at Wynberg magistrate's court, next to the police station where he has to report every day, South Africa's case against him was postponed until April.
Sir Mark is fighting alone. His passport has been impounded and he is restricted to the Cape Peninsula area. His wife came back to Constantia for a visit in October, but says the US school holidays are too short to return for Christmas. Lady Thatcher, however, will arrive soon to spend the festive season with him. It will be the first time she has seen him since she put up his £180,000 bail.
Outside the heavy gates of his thatched residence yesterday, Sir Mark was all too aware that his legal problems could drag on. "I have heard of some people waiting more than four years for a court date," he said.
Although there had been "a lot of interest", the house has not yet been sold. He is now a reluctant partaker in the lifestyle that is Constantia.Reuse content