LOS ANGELES - Yves Saint Laurent, the French fashion designer who created a bold new dress code for women during the feminist revolution of the 1970s and helped launch the era of the celebrity designer with his jet-set lifestyle, died on Sunday at 71.

His long-time friend and business partner Pierre Berge told RTL radio he had been diagnosed with a brain tumour last year and had died on Sunday in Paris. He had suffered poor mental and physical health for much of his life and had been seriously ill 'for a year', Berge added.

The funeral is on Friday in Paris.

From the start of his career at 21, Saint Laurent crafted a modern look for women that set a new standard and influenced what women wear to work and play.

He was the first to make pants and pantsuits the basic pieces of a woman's wardrobe, doing it in a way that conveyed femininity, self-confidence and style.

In contrast, for evening, he styled sheer blouses, flounced skirts and a slinky tuxedo worn over bare flesh that he famously named 'le smoking'.

His gift for redefining French couture was apparent in his 'trapeze' dress in 1958. With its narrow shoulders and wide, swinging skirt, it was a hit and a breath of fresh air after years of constructed clothing, tight waists and girdles.

For the first decade of his career, he continued to startle audiences with innovations such as a Navy pea coat, a 'beatnik' motorcycle jacket and a dress that looked like a Piet Mondrian painting.

'He was someone who was very shy and introverted, who had very few friends and hid himself from the world,' Berge told France Info radio. '(Gabrielle) Chanel gave women freedom. Yves Saint Laurent gave them power.'

French President Nicolas Sarkozy praised Saint Laurent as a creative genius. 'He was convinced that beauty was a luxury that every man and woman needed,' he said in a statement.

However, the designer was described as a tormented man who struggled with clinical depression, alcoholism and drug addiction.

Shy and exceedingly thin, he was born to a lawyer and insurance broker father and a mother who has great personal style.

He won a design competition with a sketch of a cocktail dress and was hired in 1955 by Christian Dior, who called him 'my dauphin'. In olden days, the eldest son of the French king was called the dauphin.

After Dior died of a heart attack in 1957, the House of Dior named him its head designer.

The 1958 showing of his first Dior collection - based on the widely copied 'trapeze' look - generated passionate enthusiasm that spilled into the streets.

As admiring crowds looked up, Saint Laurent, then 21, stood on the balcony of his fashion house, blowing kisses.

But in 1960, he was dismissed. House executives said he was unfit for the pressures of the job. He had been drafted into the French army that year and was hospitalised after a nervous breakdown during basic training.

Talk was that it was not so much his fragility as his fashion designs, many of them too radical a departure from the Dior image, that led to his dismissal.

In 1961, he sued for breach of contract and was awarded more than US$100,000 in a legal separation from Dior.

That year, he opened his own haute couture house with Berge, who was then his lover (they split up in the early 1980s).

It was the beginning of a success story that led eventually to a ready-to-wear line sold in the designer's own Rive Gauche boutiques; to hundreds of licences for scarves, jewellery, furs, shoes, men's wear, cosmetics and perfumes; to a public listing, the first by a fashion house, and to a host of awards, including the French Legion of Honor in 1985.

But, as he rose to prominence, his personal problems threatened to topple his career. In 1976, he suffered a major emotional breakdown and was hospitalised. Rumours were that he was taking tranquillisers with quarts of alcohol.

He also created controversy with his fragrances. In 1971, he appeared nude in an advertisement for his men's cologne YSL.

In 1977, he named one of his women's perfumes Opium, which led to charges that he was glamorising drug use and trivialising the 19th-century Opium Wars in China. Its slogan was: 'Opium, for those who are addicted to Yves Saint Laurent.' It went on to become a bestseller.

In 1992, his plans to call another perfume Champagne prompted a lawsuit by French wine-makers (the Saint Laurent company lost).

But he won a suit in 1994 against Ralph Lauren, whom he accused of copying the design for his tuxedo dress.

In 2000, Gucci bought the ready- to-wear and fragrance divisions of the House of Saint Laurent, while he and Berge kept the haute couture business until his retirement in 2002 when the couture house was closed.

By then, Saint Laurent reportedly had overcome his addictions and seemed to be in good health.

He had lived elegantly. His homes - including famous ones in Deauville, France and Marrakech, Morocco - which he shared with a succession of French bulldogs, always named Moujik, were lavishly decorated and filled with antiques and artwork by his favourite artists, who included Picasso and Christian Berard.

'Every man needs aesthetic phantoms in order to exist,' he said at the announcement of his retirement. 'I have known fear and the terrors of solitude. I have known those fair-weather friends we call tranquillisers and drugs. I have known the prison of depression and the confinement of hospital. But one day, I was able to come through all of that, dazzled yet sober.'

He is survived by his mother and two younger sisters.

LAT-WP, NYT, Reuters

This article was first published in The Straits Times on Jun 3, 2008.