Seminal supermodel

In the Victorian opulence of her Earl's Court sitting room, surrounded by cartoons, photographs and paintings of herself and her husband Leigh Lawson, and almost swallowed up by the velvety draperies on her sofa, Twiggy cuts a rather incongruous figure.

She's wearing odd purple leggings covered in a pattern of car number plates, purple Ugg-type boots and a purple jumper belted in at a still-tiny waist. Her large blue eyes are accentuated with blue pencil and the blonde hair rises above her head in fluffy spikes. She's certainly an attractive woman, despite the leggings, but it's hard to spot the je ne sais quoi that shot her to fame as the world's first supermodel almost 40 years ago and ranked her along with the Beatles as an icon of the Swinging Sixties.

Which is probably how Twiggy, 54, prefers it. Since she gave up modelling in 1970, she has carved out a successful career for herself as an actress and singer. She's had a hit in a Broadway musical, My One and Only, starred in a Hollywood adaptation of The Boy Friend and in 2001 did a brief and controversial stint as a host of This Morning. Last year, she took the lead in Sir Peter Hall's production of Mrs Warren's Profession. She's sung with Bing Crosby, danced with Noël Coward and received fan mail from Laurence Olivier (whose framed letter, of an unparalleled gushiness, hangs in pride of place by her loo). She's also got a lucrative sideline in skincare with her company Twiggy & Co: her own-brand range, Twiggy Skincare, has just hit the shelves at Asda.

So she does find it a little bit galling that her four-year modelling career remains her best-known achievement. 'What happened to me in the Sixties was so major and so worldwide and so huge, there's no way I can repeat it. But in a way, I had nothing to do with it, it just took me over. It was bizarre, it was weird, and I had no control over it. I don't think anyone could have planned what happened to me.'

In 1966, Twiggy was 16, known to all as Lesley Hornby (to all, that is, except her boyfriend, Nigel Davies, who called her 'Twigs' because of her skinny legs and had renamed himself Justin de Villeneuve because it sounded more chic) and working weekends as a shampooist at Mr Vincent's, the London hairdressers. Her real ambition was to be a dress designer. Then the photographer Barry Lategan took some photographs of her to illustrate a new hairdo given her by the iconic hairdresser Leonard, who hung one of the pictures on his salon wall. A fashion journalist spotted it, interviewed Twiggy the following week and published her article under the headline 'The Face of 66'. Within days, the Neasden schoolgirl had become a star.

'I was very, very underdeveloped for my age,' she recalls. 'I hated what I looked like, so I thought everyone had gone stark raving mad.'

She was quite different from anything that had gone before: where the Fifties superstar models had been aristocratic Amazons, she was working-class, flat as a pancake and, at 5ft 61/2in, comparatively short.

'I'd go to a shoot and they'd hold up the tights, and they'd go up to my head,' she says with a guffaw. 'I remember the first time I did a shoot in Paris, it was me and Penelope Tree, who was six foot tall. Richard Avedon was shooting it for American Vogue, and we were having hysterics because I'd put the clothes on and the waists would be around my thighs. I could only wear clothes from Ungaro and Pierre Cardin. Otherwise, everything was taken in with lots and lots of pegs and safety pins.'

But she blew fresh air into the stuffy fashion business. My grandmother, a fashion artist at the time, recalls the shock of the fashion editors when Twiggy appeared in the front row of a Balmain show with a ladder in her stocking. She remained unfazed by the world she had so easily conquered, steering clear of the pitfalls that destroyed many of her contemporaries. 'I worked damn hard,' she says. 'I didn't hang out in nightclubs, I was always getting my ten hours' sleep so I looked all right.'

Twiggy attributes her down-to-earth approach to sudden stardom to her upbringing. She is the youngest of three daughters born to Norman Hornby, a carpenter, and his wife Nell. 'We weren't rich, but we weren't poor. I always had everything I wanted.'

But her childhood was overshadowed by her mother's clinical depression and periods of hospitalisation. 'I think, looking back, that living through the war must have been absolutely terrifying. There was a bomb dropped just beyond the back garden which blew the back of the house off. My middle sister was a baby and my elder sister was six, so no wonder my mother's nerves were shattered. It was probably posttraumatic stress, and they didn't know how to deal with it then.' Her elder sister Shirley, 15 years her senior, stepped into the breach. 'She was like a second mother to me. I used to go on holiday with her and her boyfriends,' Twiggy recalls.

Her father was unimpressed with his youngest daughter's sudden superstardom. 'He was really sensible,' she says. 'He was from Bolton so he wouldn't take any rubbish. He said to me: "You're still our Les and this is all silly." '

It was he who insisted that she should have a personal manager rather than signing up with a modelling agency. 'He said, "If you're going to do this, you've got to have someone with you all the time," and he was right. If I think back to all the louts who could take advantage of a very innocent 16-year-old girl... but nobody got near me. My manager was like a bodyguard, really.'

Not that this was an entirely positive development in Twiggy's career. Her manager and boyfriend of seven years was Justin de Villeneuve (later to be the father of London socialites Poppy and Daisy), who was serially unfaithful and, says Twiggy, 'ended up ripping me off financially'.

The money she earned was spent, she says tartly, on 'lots of posh cars and Savile Row suits'. Is it galling to think about it? Twiggy shrugs. 'No, because it's done and past. We haven't seen each other for years and years, but if we met, I'm sure we'd say hello.' She's more hands-on with her money now. 'I've learnt from those days. You get very ripped off in this world of commerce.'

In 1970, at the peak of her fame as a model, she met Ken Russell who cast her as the lead in his film of The Boy Friend. 'I could have gone on modelling probably for another ten years,' she says. 'But I enjoyed acting more than modelling and I got two Golden Globes for The Boy Friend.' Seamlessly, she went from being a Swinging London face to a Hollywood star, and made the break from de Villeneuve.

Her subsequent venture into romance was little more successful. She fell for Michael Witney, her rugged co-star in a thriller, W,and 20 years her senior. After they married, in 1977, she found out he was an alcoholic. 'He was a lovely man,' she says, 'but he had a major problem and it ended up killing him.'

They had a daughter, Carly, who's now 24 and an animator, but Witney's drinking spiralled out of control. By the time Twiggy was 31 and a star on Broadway with the show My One and Only, Witney was becoming increasingly violent. After one row when he punched his fist through a plasterboard wall, Twiggy left, taking Carly with her. Witney joined AA, but he died of a heart attack in McDonald's where he had taken Carly to celebrate her fourth birthday.

If Twiggy skates briskly over this period in her life, it's not to be wondered at; especially as Carly is in the flat as well. She comes in to bid an affectionate goodbye to her mother (who's off the next day on a business trip to Tokyo), and is a polite, pleasant young woman with a completely normal physique - none of her mother's Bambilike build. They are clearly very close. Twiggy says she was a strict parent.

'I think you have to give your children a structure; they push you for the rules.' She often brought Carly to matinee performances where she was mothered by all the chorus girls. And then, on a trip to London, Twiggy was invited to a dinner party by the actor Robert Powell and his wife, and introduced to a fellow actor, Leigh Lawson, whose best-known role was as Alec d'Urberville in Roman Polanski's Tess. In fact, they had met before, when Leigh was married to the actress Hayley Mills. 'We had dinner after a John Denver concert. I remember I thought Leigh was very handsome. It didn't cross my mind that, ten years later, we'd be seeing each other.'

Understandably wary, she took her time committing to someone else. 'I was 35, he was 42 and you're much more careful than you are at 20. And I had a daughter and I'd been through whatever with Michael. So we dated, and it was really romantic. We went to the theatre and the cinema and, after about three months, we knew.'

At the time, Leigh's son Jason was eight, and Carly was six. 'They got on magically from day one.' Indeed, they now share a flat and, along with their stepbrother Crispian Mills (who found brief fame as the front man of Kula Shaker), have a family dinner at Twiggy's house every week.

Twiggy and Leigh married in 1988 in Sag Harbor, Long Island, under a weeping willow tree and, according to Twiggy, have been happy ever since. They turn down acting jobs to spend more time with one another and work together both onstage and in the skincare business with nary a cross word. The only reason to doubt this idyllic picture is that Twiggy likes to put a positive spin on everything. Even her stint on Good Morning, which saw her criticised for being wooden and leaving the sofa after two months, she describes as 'an extraordinary experience'.

'I don't regret doing it: I learnt a lot. It was a very interesting episode. And John Leslie was the nicest man I've dealt with in that arena, and I feel for him.

'The problem was between me and one woman. [She's referring to the then controller of ITV's daytime TV, Maureen Duffy.] We just didn't get on and after I left, she was axed and high-tailed off to Australia.'

Since then, she says, she's been offered four presenting jobs that she's chosen not to take. 'If you're an actor and you do a film that everyone trashes, you're not going to not make another film. The problem with someone like me is, because of my silly name and because I'm well-known, I'm a very good headline.'

It has occurred to her, she says, to abandon the Twiggy name altogether. 'I did think in the mid-Eighties that this is stupid, a woman of my age being called Twiggy. But I'm lumbered with it. It did annoy me for a while but I came to terms with it. Twiggy was such an enormous thing that happened, everyone remembers it. And at least it's a nice memory: it's not like I murdered someone.' She's cackling hugely again, but you know that Lesley Hornby remains as unimpressed by the Twiggy phenomenon as she has always been.

Twiggy Skincare is available from Asda stores nationwide