Minimalist to the last, Klein takes leave of the stage he has dominated

Calvin Klein, the most famous name in American fashion, formally departed the catwalk last night to make way for his successor, Francisco Costa. This was the younger designer's debut collection for the label, although he has worked alongside Klein for the past year.

True to understated form, the changeover was confirmed without fanfare. Klein is, after all, the man who put American minimalism on the map. Still, it is unusual. Fashion's greats generally bow out in a blaze of glory. Witness Saint Laurent's huge retrospective swansong collection of January 2001. Shown at the Pompidou Centre and broadcast to the Parisian public on huge screens outside, it made the front pages the world over.

For Klein, though, there was nothing more than a press release coolly announcing that Costa, who cut his fashion teeth at Gucci, Balmain and Oscar de la Renta, would be assuming the role of womenswear designer at the label. Italo Zucchelli is designing the menswear.

Although the label's namesake will apparently continue to be involved at some level, no title has been confirmed and what his role is unclear.

Whichever way you look at it, this marks the end of an era.

The New York fashion industry has long been dominated by the mighty Donna Karan, Ralph Lauren, Calvin Klein triumvirate. While Karan has made a name for herself as a woman who designs with the needs of other women in mind and Lauren's success story relies on a rose-tinted view of Ivy League style, Klein dressed uptown New York in suitably restrained and elegant manner. His client was the ultimate social X-ray. The late Carolyn Bessette was famously part of his PR machine before her marriage to John F Kennedy Jnr.

Klein's influence stretched far beyond that, however. Calvin Klein was the first name to peep over the waistband of low-slung jeans the world over. He has since spawned endless imitators. His unisex scent, CKOne, was the fragrance of the 90s. The advertising campaigns that promoted the name, meanwhile - from a young, naked Kate Moss to Brooke Shields coyly announcing "nothing comes between me and my Calvins" - are some of the most ground-breaking and iconic of our age. Just like the brains behind them, they are the last word in metropolitan cool.

The past year has been an eventful one for the designer. In December 2002, his company was bought by Phillips-Van Heusen for $400m (£250m) in cash, plus $30m in stock and up to $300m in royalties tied to revenues over the next 15 years.

Less than three months later, Klein was making headlines again. This time, it was the designer's personal life, not his business that came under scrutiny when, on 24 March, he interrupted a New York Knicks basketball game at Madison Square Gardens. Two minutes before the finish. Klein was seen wandering along the side of the court and grabbing the arm of the Knicks' swingman, Latrell Sprewell. "He was trying to say something but he was just mumbling," Sprewell said afterwards. For his part, the designer subsequently admitted to a continuing struggle with substance abuse. For the time being at least, Klein and his successor have nothing but good to say of each other. "I've worked closely with Francisco this last year and I'm confident he will turn out a wonderful collection," Klein said.

The Brazilian-born Costa gushed in response: "It's almost like having an alter ego. He is straightforward which is great. That is the most modern thing about Calvin. There's no messing around."

Today, Calvin Klein the global brand is much bigger than the man who started it, overshadowing anything as elitist as designer clothing by far. It is a measure of the state of the fashion industry today that the machine that drives the Calvin Klein brand will do doubt continue just as it has done with or without its founder in tow.

THE EXPANDING CK BRAND

Perfume

Launched in 1995, the unisex perfume became the signature scent of the decade. Embraced by the youth market, sales even outstripped Chanel No 5. The "CKone approach" became a synonym for cross-gender marketing. CKbe followed in 1997.

Advertising

From "heroic chic" to the clean-cut all-American dream, the brand pioneered high-class black and white photography, attracting names such as Brooke Shields and Kate Moss.

Underwear

Became the must-have underpants for men thanks to raunchy adverts.

T-shirts

CK logo on a black, white or grey background made them instantly recognisable, though a target for pirates.

Eyewear

Applied "less is more" philosophy to spectacles and edgy sunglasses. Immortalised by Uma Thurman in the film The Avengers.

Claire Hall