During his 50-year career as a fashion designer, Yves Saint-Laurent, who died on 1 June, 2008, aged 71, made his name one of the best-known in the world and one that the fashion world would learn to recognise as the vanguard of their trade.

He was arguably the most influential figure in his field, not only because of his zeitgeist-capturing styles, but also for bridging the gap between haute couture and the high street with his Rive Gauche boutique chain.

Despite being somewhat retiring in character, he became a liberal icon thanks to his empowerment of women through fashion and putting black supermodels onto the catwalk for the first time. Thus his influence reached beyond the usual boundaries of the industry and earned him recognition around the world as a cultural doyen.

Yves Henri Donat Mathieu Saint Laurent was born on 1 August, 1936, in Algeria. His father was president of an insurance company and also owned several cinemas. He inherited his fashion sense from his mother with whom he spent most of his childhood owing to his father’s business commitments.

Another love of his was the theatre, but being too timid to act himself, he consoled himself by making costumes for his two younger sisters to wear in their recreation of popular plays. As he neared maturity, his father tried to talk him into becoming a lawyer, but he was headstrong and determined to go into fashion.

He studied first at the Chambre Syndicale de la Couture, but felt frustrated by the syllabus so left after a few months, a sign of his future maverick status. He was vindicated when he won the International Wool Secretariat design competition for a sketch of a cocktail dress – the cocktail dress in question was similar to one none other than Christian Dior was working on himself, so, spotting the potential for cohesion, he hired the precocious 17-year-old.

Within a matter of years Mr Saint-Laurent had become Mr Dior’s right hand man – Dior even described him as his " dauphin ". It was a fitting nickname, for when Mr Dior died of a heart attack aged just 52 in 1957, Mr Saint-Laurent succeeded him as chief designer and saved the company from financial ruin.

In 1960 he was conscripted into the French army and sent to fight in Algeria, the country of his birth. He fitted badly in the forces and was subjected to severe mental abuse from other soldiers. After three weeks he suffered a mental breakdown and was hospitalised. He attributed later substance abuse and depression on psychiatric drugs he was given in this time.

He had handed over the reigns of Dior to his assistant Marc Bohan when he was called up, but was unable to get his job back when he returned to health, leading to a 680,000 franc settlement. In 1962 he and his lover, the businessman Pierre Bergé, launched the Yves Saint-Laurent label.

Mr Saint-Laurent’s greatest talent was anticipating trends, allowing him to shape them during their formative stages. In the early ’60s he was a pioneer of beatnik chic, a minimalist look that originated in the jazz cafes of Paris and San Francisco and would be a precursor of the hippy fashion of the latter part of the decade.

Another famous creation of his was the trouser suit, the must-have item of women’s fashion in the ’80s which he first conceived 20 years earlier. His safari-look collection made khaki the new black in 1970 and he turned androgyny into an alluring concept long before punk swept away that particular taboo with his le smoking tuxedo jackets.

Politically he made black the new white when he put the African model Iman on the catwalk in 1976 and described her as his "dream woman". If that was a brave move, calling a perfume Opium the following year was downright audacious, particularly when he advertised it "for those who are addicted to Yves Saint Laurent".

He himself was addicted to alcohol, tranquilizers and other drugs at various points in his life, a decadence that probably served the same purpose as his lavish houses and enviable art collection – staving off loneliness and depression. Yet his personal problems rarely affected his creative flow – indeed, at his lowest ebbs he would produce his most glamorous outfits while happier periods would reap retrospective silhouette styles, as if fashion was a counterbalance to his emotions.

His ability to operate across the full spectrum of fashion styles was central to the stroke of genius that was Rive Gauche, the boutique that made versions of haute couture creations available off the rack for the first time. These days the major designers compete for contracts from the high street stores, but Mr Saint-Laurent’s gift of glamour to everyday women made him the industry’s single most influential figure, not to mention one of its richest.

His standing culminated in the Metropolitan Museum of Art in New York staging an exhibition of his clothes in 1983, the first collection of its kind and proof that he had created what was both art and a saleable commodity.

In 2001 his life’s work earned him the Légion d'honneur, France’s highest decoration. The following year he retired as the head of the YSL fashion house, closed down the company and sold the rights to his name to Gucci. "I am very sad to put an end to a love affair that has lasted for 40 years," he said. He had since been highly critical of designer Stefano Pilati for sexualising the YSL prêt-à-porter range and diminishing its original elegance.

He died at his home in Paris after a long illness, leaving behind a legacy of unparalleled splendour.