The Guess? Campaigns had become notorious for their classic pin-up images. Guess? Girls looked like they should decorate Flying Fortresses or brighten up the barracks of lonely soldiers, reminding them what pleasures await should they get through the next skirmish and make leave.

   Marciano spotted a full-figured 15-year-old who had just started modelling in French magazines. She looked a little raw and rustic, serving-wench saucy. She had a body like no other girl he had seen, curvy but not comically so, demanding exaltation. Guess? Could make it so. The girl was Laetitia Casta and she has become the greatest of all Guess? Pin-ups and a major star in both Europe and America.

   Casta was born 21 years ago in Port Audemer in Normandy and was spotted, in the way that models are, on a beach in Corsica. Since her first Guess? Campaign in 1994, she has worked for Ralph Lauren, lingerie legend Victoria's secret and made a couple of appearances in Sports Illustrated's Swimwear edition (a gig guaranteed to plant you deep in the affections of American men). But it is the pin-up aesthetic of the Guess? Ads that serves her best, exaggerating the obvious, rendering her cartoon-cute and innocently sexy, a primal beauty.

   Close up though, she is not at all obvious. She is petite. And her curves, while still remarkable, are nothing like ludicrous. She is the colour of a Ben & Jerry ice-cream, toffee and pecan or something similar. Her features are strong and certainly Gallic. In the flesh, she is not a simple proposition at all.

   Casta eats like a pig or, as she has it, 'I eat more than my dog.' Her English is good to impeccable and she speaks it in a heavy French accent that isn't as sexy as it should be. She is belligerently laid-back about her success. 'If my potato is there,' she says, pointing at her huge pile of potatoes, 'I will take it. If it is not, I will not sing about it.

   'Some people are desperate to do this or that but that is not natural. I think that you should just choose things as they come along. The main thing is to be happy. And to have fun. People have big plans to be acting or whatever -- to me it doesn't mean anything.'

   This is a little disingenuous as she can be seen this summer in Asterix And Obelisk Against Caesar, a major French turkey starring Gerard Depardieu. Her involvement, though, was pretty minimal. She spent three days on set, opposite the grand fromage of French cinema.

   While not in front of the camera, she enjoyed messy food fights with the crew. I'm sure they enjoyed them equally. Later in th eweek she is set to drive down to Bordeaux for four months to film a movie about a young French resistance fighter. This time she has the lead role.

   Despite these acting adventures, her comme çi comme ça shrug seems genuine. Many girls in her position, embarrassed by the diva antics of some of their peers, bleat about their normalcy. And you don't believe a word of it. With Casta, you sense that this is her central struggle. Behind the act of indifference, there is a fear at what her industry can do to people.

   'All of this has been a test,' she says. 'There are so many things that I have been through that I did not know were going to happen. You have to give so much. But when I started I said I will never change, that was my goal. I don't want to be a big head because I would lose everything, my soul.'

   She is frank about how much she relies on her parents and her family. 'Without them I would be completely lost. It would be like -- shit!' She has a terror of losing them and being set adrift.

   She has been living in London for a year. She is less well known here and gets less grief on the streets. Not that she can't handle unwanted attention. 'If people recognise me and they are nice then that's fine. If they are mean, then I punch them.' She means this. 'Sometimes people just take pictures of you. One day, one guy just would not stop. I said, "Please, do you mind if you don't do." But he carried on, so I take my bag and ... [signals rabid granny-style bag attack]. He didn't understand that sometimes you have to respect the quiet of life. I don't mind the public because they keep me in work and I respect them and it's my job and I understand that. But the people who take photos when you don't want them to, I kill them. Pow! Pow!' And did the guy leave her alone? 'Oh yeah, he ran. He ran!'

   Fundamentally, she's a little embarrassed by it all, as if she can't understand why displaying what she has in the way that she does should provoke such a reaction.

   Casta doesn't go out much, preferring to mooch around her flat. She wants a simple life and to have a few kids along the way. 'I want, I will, have four or five kids. I want to be a good mother. What I want in my life is for it to get really simple and for me to get happy. And nothing else. And if everything stopped, I don't care!'

   Of course it's not going to stop, not yet. She's set to be the most successful slice of unfeasible French womanhood since Bardot. Or at least Beatrice Dalle. Her plate is still full of potatoes.