PARIS • French fashion designer Sonia Rykiel died on Thursday at the age of 86, mourned by President Francois Hollande as an inventor of "an attitude, a way of life".

Rykiel was a rare woman at the top of a world dominated in the 1970s, 1980s and early 1990s by men such as Yves Saint Laurent and Karl Lagerfeld, inspiring female self-empowerment through her tongue-in-cheek style, notably brightly striped sweater dresses.

"It is a sad day but Sonia Rykiel leaves behind her an extraordinary legacy," Mr Jean-Marc Loubier, chairman and chief executive of First Heritage Brands, parent company of the Sonia Rykiel label, told Reuters.

"She was a pioneer who helped women and society evolve."

Instantly recognisable by her bushy red hair, Rykiel founded her fashion house in the literary Paris quarter Saint-Germain-des-Pres in 1968, when France was rocked by violent student riots, aiming to counter stiff, bourgeois dress codes, with inside-out stitches and extra-short skirts.

She made her breakthrough in 1962 with the so-called Poor Boy Sweater, a shorter skinny sweater with long sleeves for women.

The Poor Boy met resistance at first, partly because of its bulky stitches. But all that changed in December 1963 when Elle magazine featured 19-year-old French pop idol Francoise Hardy on its front cover in a skimpy striped red-and-pink Rykiel number.

It became a sensation.

Brigitte Bardot and singer Sylvie Vartan were photographed in Rykiel sweaters and Audrey Hepburn herself went to the shop and snapped up five.

"I wanted to make a sweater for a specific woman - myself," Rykiel wrote in her 2012 memoir N'oubliez Pas Que Je Joue (Don't Forget That I Am Acting). "(I) couldn't find the clothes I had in mind for a woman of 30 who has come home from work to go to the theatre and then wants to go out for dinner afterwards.

"I had the sweater made in a factory in Italy and it was tiny; it was just how I wanted it."

In the 1970s, Women's Wear Daily called Rykiel "the queen of knitwear" even though she never learnt to knit and had not studied fashion.

Over the decades, she branched out but always remained true to knitwear, using humble jerseys and cottons with fluid, innovative shapes. She blurred the divide between day and evening wear and always favoured pants over skirts.

In 1985, then French President Francois Mitterrand named Rykiel a chevalier of the Legion of Honour.

In 2008, former President Nicolas Sarkozy named her a grand commander of the legion for lifetime service to fashion, a major national industry.

Mr Hollande's office said: "She had invented not only a style but an attitude, a way of life and gave women freedom of movement.

Mr Ralph Toledano, chairman of the French Federation of couture, ready-to-wear designers and fashion designers, said: "Sonia Rykiel was a great lady of exceptional talent, she embodied the rebel and independent spirit of Paris and Saint-Germain-des-Pres.

"Her style expressed the quintessence of a free woman and her heritage is all the more pertinent in light of the current news and events," he said, a reference to the decision by many French seaside towns to ban burkinis.

Born Sonia Flis in the upmarket Paris suburb of Neuilly, she started her career as a window dresser in a Parisian textile store at the age of 17, but had no formal training.

In 1953, she married clothing boutique owner Sam Rykiel, with whom she had two children, Nathalie and Jean-Philippe, who survive her. She and Sam Rykiel later divorced.

In 1995, she passed on the creative and management leadership to Nathalie. She retired in 2009, but continued to attend fashion shows and write.

She played herself in Robert Altman's 1994 satire, Pret-a-Porter, which was filmed during Paris fashion week.

In her 2012 memoir, she disclosed that she had Parkinson's disease for 15 years and had kept it secret, even from her family, until she could no longer hide the symptoms.

In 2012, the family sold control of the label to Hong Kong investors, but Nathalie still works as a consultant for the fashion brand.

Within the French fashion industry, Rykiel will be remembered as a visionary who helped cement Paris and, in particular, the Left Bank, as the capital of couture.

She described her philosophy as "la Demode", a contraction of "deconstruction" and "mode".

In 2008, 30 of the world's top designers paid tribute to her at an exhibition marking her 40 years in the business, offering their own take on the Sonia Rykiel look.

"She abolished hemlines and linings, she invented knitwear, she made clothes that were reversible, she used layering," Mr Olivier Saillard, who curated the retrospective of her work, said at the time.

"She was chic and cool, very Left Bank," said legendary French designer Jean-Charles de Castelbajac.

Jean Paul Gaultier, another lover of stripes, paid tribute to her "revolutionary" work for women, saying: "Thank you for the inspiration and style."

REUTERS, AGENCE FRANCE-PRESSE