Published in The Daily Telegraph, 2008

On Friday, Mustique — a 1,400-acre private island in the Grenadines — celebrated a very special 40th birthday: that of The Mustique Company, the consortium of residents that has run the island since 1968. Colin Tennant, now Lord Glenconner, bought Mustique for £45,000 a decade before founding The Mustique Company and began turning it into a glamorous holiday hideaway.

But what really put Mustique on the map was the arrival of Her Royal Highness the Princess Margaret in the sixties. Lord Glenconner had given her a 10-acre plot on the island as a wedding gift and she commissioned theatrical designer, Oliver Messel, to build her a villa, Les Jolies Eaux.

As Lord Glenconner once told me: “She filled it with things she had seen at the Ideal Home Show: there was an awful lot of Formica.” You can rent Les Jolies Eaux, though it has been extensively refurbished so there is little trace left of its former owner.

In the early days, life on the island was simple: the roads were little more than tracks; fresh water was scarce, and the mosquitoes were fiercesome. But the infrastructure improved once Lord Glenconner began to sell land to carefully vetted, mostly British, buyers and, by 1969, there were proper roads and what is surely one of the world’s chicest little airports, complete with thatch-roofed departure/arrivals hall and a pristine white picket fence.

Princess Margaret adored Mustique because it was somewhere she could let her hair down. And the parties at Les Jolies Eaux — the only property she ever owned–— were legendary. Regulars included her cousin Lord Lichfield, who had a villa nearby, gangster John Bindon — with whom Princess Margaret is rumoured to have had an affair — and Mick Jagger. It was here, too, that she conducted her affair with Roddy Llewellyn, a landscape gardener 17 years her junior.

Nude sunbathing was de rigueur, and lavish picnics were set out on the beach on fine china. MI5 apparently kept a discreet watch from a nearby hilltop.

Princess Margaret gave Les Jolies Eaux to her son, Lord Linley, when he married in 1998, but, much to her distress, he quickly sold it.

Lord Glenconner severed his connections with the island in the mid-1970s and has made no secret over the years of his distaste for Mustique and the people who live there now.

But, as Prince William and girlfriend Kate Middleton’s visit last weekproves, the island continues to attract the rich and famous. Mick Jagger has a villa there; as do Tommy Hilfiger, Bryan Adams, Shania Twain, the Guinness family, and Belle and John Robinson, owners of Jigsaw.

The reason the wealthy still flock here is partly to do with the island itself — it has seven white-sand beaches, an average daily temperature in the mid-80Fs and is rarely troubled by hurricanes. But it is also due to The Mustique Company which controls almost every aspect of island life, from the villa rentals to the watersports. It has limited the number of villas that can ever be built on the island to 120; refuses to allow the little port to be extended or the airport modified so that it can accept private jets; and jealously guards the privacy of its residents.

Bylaws on the island include — how Princess Margaret would have scoffed — no nudity. They also stipulate: “when walking about the island in bathing-suits, please also wear cover-ups such as T-shirts or pareos”. Boats are not permitted to land on the beaches and picnics are allowed in designated areas only. Most people travel around by Mule — the local term for a golf cart — and the speed limit is set at a stately 20mph. If you have a criminal record or are undesirable in any way, you can forget it. Needless to say, paparazzi, beggars and beach vendors are all banned.

However, the right type of visitor is welcomed. Seventy of the island’s 100 private villas can be rented from $4,250 to $150,000 (£2,200 to £7,700) a week, or you can stay at one of two hotels, the tiny Firefly or the sumptuous Cotton Club, which Messel also designed.

However, anyone who comes expecting the hedonistic party island of Princess Margaret’s day, will be disappointed — unless you happen to know Tommy Hilfiger, who threw a party for Beyoncé in 2004 and was pushed into the pool fully clothed by Bryan Adams.

This is a quiet island. There are none of the noisy Caribbean staples: no jump-up on a Friday night, no pungent fish fry and no reggae belting out from rum-shacks on the beach. Apart from the odd foray to the famous Basil’s Bar or to the beach, residents tend to stick close to their villas or their neighbours’ villas. The Mustique Company throws a cocktail party at the Cotton Club on Tuesday nights, but it is a sedate affair.

Sanitised? Certainly. Dull? Just a little. But the attraction of Mustique for Prince William and Kate Middleton, no doubt, is that it is one of the few places in the world where they can stroll around without being watched and photographed.

It is also one of the safest places : while the murder rate escalates throughout the Caribbean, the only murder in Mustique’s recent history occured 10 years ago when a French heiress was found stabbed to death in her villa — a crime that has never been solved.

So happy 40th birthday, Mustique. It is comforting for many of us to know that in an ever-changing world, there are still some things that don’t change very much at all.