My favourite thing to do on a weekend?” muses Iman, sitting back and fingering a large diamond dropping into her golden cleavage. “I’d say cooking David some shepherd’s pie. He’d probably choose a fry-up and British papers, but I’m trying to keep his cholesterol down.”

Cholesterol and fry-ups aren’t words normally associated with two of the world’s most extraordinary rock and fashion legends. Well, welcome to the real — and very romantic — world of Mr and Mrs Bowie. As these intimate portraits, taken for a new Tommy Hilfiger campaign, show, the two have one of the most inspirational marriages in showbiz.

But when Iman and Bowie first met, in 1990, they were both at an emotional low. Bowie was the iconic rock star from Brixton, with a career dogged by drugs, drink and depression, despite an estimated fortune of £500m. Iman was a Muslim Somali from a diplomat’s family, with five languages, an education in political science and a career in modelling. Their backgrounds could not have been more different.

Yet, when they met, neither could have been emotionally more ready for commitment. Bowie had pulled himself, without therapy, from depression and being “as near to defeat as at any time in my life”. And Iman was looking for a new life, having tired of 14 years of modelling and flying all over the world.

After just one night (a blind date, organised by their hairdresser friend Teddy Antolin, in Los Angeles), Bowie declared she was the woman for him. By the end of the evening, he had decided to marry her, and was waiting for her on the runway the next time she returned from a trip away. “It was so lucky that we were to meet at that time in our lives, when we were both yearning for each other,” says Bowie. “She is an incredibly beautiful woman, but that’s just one thing. It’s what’s in there that counts.”

What’s “in there”, Iman confesses, is “the wonderful realisation that I have found my soul mate, with whom sexual compatibility is just the tip of the iceberg. We have so much in common, and are totally alike in a lot of things”. It’s not a love of music, or fashion, or the fact that “like David has his feminine side, I have a masculine side”, she insists, but the more old-fashioned values: romance, family, commitment.

Bowie’s proposal, for example, was the most old-fashioned celebration of romance that his considerable fortune could buy: a boat on the Seine in Paris, with a private pianist and dinner for two, and an 18th-century Florentine ring (which, in spite of “owning more jewellery than I can wear”, is still Iman’s favourite piece). Their wedding ceremony, in Italy, in June 1992, was a family affair, with Bowie’s son Duncan as best man, and fine gold wedding bands (after 11 years of wedlock, Iman still begrudges removing hers for fashion shoots, “because it’s moulded to my hand”). Even their bodies have been tattooed with dedications to each other: she with Arabic lettering for David around her belly button, he with a Japanese inscription on his calf. But then, she says, they are “an inseparable part of each other’s lives”.

They even celebrate the 14th of every month, the anniversary of their first date. During the shoot for these photographs, in Holland, Bowie ensured that “lots of silly presents” were sent over to their hotel on that day. “We work hard at keeping the relationship alive,” he says. “We talk to each other continuously. We have complete and absolute faith in each other.” And is he a romantic? “I guess I am. I’m a flower-sender, and I remember anniversaries. I am quite good on that score.”

After years of trying for a baby, and IVF treatment, in 2000 Iman had a daughter, with Bowie there to cut the umbilical cord.It was something, he says, that changed his life. When he’s at home, he gives the three-year-old breakfast and takes her to the park before he goes to the recording studio (although, Iman says with a chuckle, “changing diapers is not really his thing”).

Even when he’s touring, he calls her every day. They don’t miss the party scene at all, Iman claims, and in New York they can live anonymously, “going to the park and sitting in cafes. We’re just ordinary people. Our life is domestic. I look at recipes and cook whatever takes our fancy — Chinese, Italian and Thai”.

After the shoot, Tommy Hilfiger said he had never expected the chemistry between them to be “quite so incredible”. When the music started to play — a mix, from rap to rock’n’roll — “They just fell into this relaxed, comfortable way with each other. It’s quite clear that they are totally in love, and easy with who they are,” he says. “It’s a much deeper relationship than you could ever expect.”

So, will they ever consider leaving the good times that New York offers for the home country Bowie admits he misses? “Who knows?” Iman sighs. “What’s home? At the moment, it’s New York, which we love, and where I’ve been for more than 25 years. But really, home is wherever David is.”

When it comes to plain old-fashioned romance, you can’t get much sweeter than that.

Tommy Hilfiger H Clothing line will be launched in the UK in the autumn

Times recommends

• Who killed Jade Goody?
• Daisy Goodwin: This is better than real sex
• Foods that can help to prevent swine flu