The man who dressed the world bows out

At a packed press conference at midday tomorrow in Paris, Yves Saint Laurent, the last great couturier, is expected to announce his retirement. By the time he addresses the assembled press, speculation about the announcement will have become frenzied, but yesterday his office still would not comment, claiming that even staff close to him are unaware of the reason behind such a move.

Saint Laurent is no stranger to such excitements. His 30th and 40th anniversaries were celebrated amid a cloud of conspiracy theories. The designer, who turned 65 last year, has suffered ill health for many years. In 1999, he sold his ready-to-wear branch to the Gucci Group. But Saint Laurent has continued to produce twice-yearly haute couture collections – for which each garment is hand-cut, sewn, beaded, feathered and embroidered under his supervision – in his own name, invariably to widespread acclaim. His spring/summer haute couture collection is due to be shown in Paris on 23 January. The belief that it could be his last has only been fuelled by the airing of a documentary the following day on Canal Plus in which Yves's mother, Lucienne, talks about her son for the first time. There will also be a major retrospective of his work at Galerie Lafayette later this year.

As the last of his kind – Coco Chanel, Christian Dior and Cristobal Balenciaga died long ago – Saint Laurent has appeared, for many years now, to be living in a different era. His shows are a million miles away from the media circus that fashion has become. In the grand ballroom of the Hotel Intercontinental, guests still take their places on tiny, gilt-edged seats; any press presence is deliberately low key. If there were ever any doubt that this was about anything but the sheer beauty of clothes – as opposed to the marketing potential of personalities, fragrances and handbags – journalists are told to turn off their mobile phones for the duration. When Saint Laurent appears on the runway with the final bridal gown, he is surrounded by an army of aides intent on protecting him from intrusive microphones and cameras. Interviews are unheard of. It would not be overstating things to say, then, that his retirement would mark the end of an era.

Yves Henri Donat Mathieu Saint Laurent was born on 1 August, 1936, in Oran, Algeria. His father, Charles, owned a chain of cinemas. His mother was a famed beauty who doted on her son. She was also his first muse. "I can still see my mother," Saint Laurent once wrote, "about to leave for a ball, coming to kiss me good night, wearing a long dress of white tulle with pear-shaped sequins."

Although Saint Laurent has described his childhood as idyllic, he also claims that he was overly sensitive, even neurotic, from an early age, and bullied by his classmates due to his homosexuality. But if the root of the mental breakdowns and drug and alcohol abuse that have plagued him throughout his life can be attributed to this, it also furnished him with an unswerving desire to succeed. "I told myself repeatedly, 'One day you will be famous'," he has said. "My name will be written in fiery letters on the Champs- Elysées." Fame was not long in coming. At 17, Saint Laurent won a prize in a competition for the Wool Secretariat for a little black cocktail dress. Not long after that, he was introduced to Christian Dior, who invited him to work with him at the height of his powers with the New Look.

When Dior died suddenly less than two years later, Saint Laurent found himself, aged 21, presiding over France's most high-profile fashion house. He is still the youngest person ever to be made couturier. In 1960, he was drafted into the army and promptly had a nervous breakdown. In 1961, when Dior failed to reinstate the designer after his illness, Saint Laurent successfully sued the house for breach of contract and set up his own business with the proceeds. He rented a two-room atelier with Pierre Berge, his business partner and lover, and began work with a few staff poached from Dior.

In the Sixties and Seventies, Yves Saint Laurent opened the first ready-to-wear designer boutiques under the name Yves Saint Laurent Rive Gauche. In 1966 he designed "le smoking", a man's tuxedo reinterpreted to relieve women of frothy evening wear, and caused a scandal by sending out a model bare-breasted except for a black chiffon shirt.

Saint Laurent introduced the skinny sweater, the leather biker jacket, the safari jacket, ethnic influences from Africa to India, and fashion inspired by art to the fashion lexicon. It is safe to say that there is not a modern woman or man's contemporary wardrobe that is untouched by his influence, nor a familiar item of clothing that he hasn't pioneered. To honour Saint Laurent's contribution to culture, the last ever five, 10 and 50 French franc pieces minted before the introduction of the euro were stamped with his portrait.

In 1989 the YSL Group was valued at $500m (£350m) after going public on the Paris stock market, following an earlier $180m private placing of share investors. Four years later, Elf Sanofi acquired the company for $650m. Saint Laurent had made the headlines once more, but this time it was over the high purchase price and the profits made by himself and Berge, which fuelled suspicion that the deal had been orchestrated by François Mitterand as a favour to the latter, his close friend. A year later, Berge was fined Fr3m by the French authorities for insider trading, although this amount was reduced to Fr1m on appeal.

Today, the YSL Group is owned by Gucci, which acquired Sanofi in November 1999. Gucci's creative director Tom Ford is currently applying the same voracious makeover to the ready-to-wear Rive Gauche label that he did to the flagging Gucci brand in the mid-Nineties, and is making it the tag to see and be seen in once more. The haute couture side of the business, however, remains in the hands of Saint Laurent.

Pierre Berge once said: "When the time comes, I will decide, without hesitation, to close down the couture house. I must do that for Yves. It is a nonsense to carry on without him. Look at Chanel without Mademoiselle Chanel, and Dior without Christian Dior. It is more than nonsense; it has no integrity. It is a sham."

A very lucrative sham, indeed. Dior is today presided over by the brash young British designer, John Galliano. Chanel, meanwhile, is designed by Karl Lagerfeld. It remains to be seen whether Berge will remain true to his rather melodramatic word. The closure of the house and any profits that might go with it would, after all, be a fitting tribute to a man who has contributed more to fashion than any other, before or since.

The heirs apparent to Saint Laurent's throne

John Galliano

Brought up in Streatham, South London, Galliano, 41, graduated from Central Saint Martins in 1984 and later moved to Paris. In 1995, he was appointed as couturier at Givenchy. A year later he moved to Christian Dior. He still designs both Dior and his own-name collection; his unbridled eclecticism and unashamed forays into fantasy continue to be met with hyperbole.

Jean Paul Gaultier

Gaultier, 48, is one of the last remaining French-born designers on the Paris fashion circuit. Trained under the great couturiers, cutting his teeth at Pierre Cardin and Jean Patou. Famous for dressing Madonna in a conical bra, he proved himself a serious contender for YSL's crown when he set up his own couture house in 1997.

Rei Kawakubo

Rei Kawakubo was born in Tokyo in 1942. When she was first invited to show in Paris in 1981, her clothes – huge, dark, deconstructed shapes in boiled wool peppered with holes – caused a minor outrage. She has since been recognised as a woman who refuses to bow down to any preconceptions of what an item of clothing can or cannot be.

Karl Lagerfeld

Born in Hamburg in 1938, Lagerfeld emigrated to Paris in 1952. He was a design assistant at Balmain and art director at Jean Patou, but is most famous for having breathed new life into the mighty Chanel label after the death of its namesake. Lagerfeld invests Chanel with a postmodern twist: big, furry ski suits branded with the famous interlocking Cs.

Giorgio Armani

Born in 1934, Armani dressed the 1980s. His minimal aesthetic – softly structured trouser suits in all shades of greige – defined that era. No longer seen as innovative, but makes up commercially for any loss of creative clout. He is one of the richest designers in the world and the second richest man in Italy.

Tom Ford

Ford, 40, has an extraordinary nose for style and setting trends. In the mid-1990s he transformed Gucci, then a tired status label, into the designer tag to be seen in. Now doing the same for the YSL Rive Gauche ready-to-wear line. Orchestrated Gucci buy-outs of Stella McCartney, Alexander McQueen and a 50 per cent stake of Balenciaga.