The first of two new museums dedicated to Yves Saint Laurent has been opened in Paris, offering a glimpse into the world of the shy, mysterious man who revolutionised women’s fashion.

The Paris mansion where Saint Laurent shook up dress codes for more than three decades has been turned into an exhibition space for his haute couture creations. A larger museum, also paid for by the foundation set up by his late lover and business partner Pierre Bergé to safeguard Saint Laurent’s legacy, opens next month in Marrakesh.

The Moroccan city was one of the couple’s favourite places, where Saint Laurent would often sketch out his collections.

“Coco Chanel liberated women, but Yves Saint Laurent gave them power,” Bergé once said. He did this by appropriating the symbols of the traditional male wardrobe – dinner jackets, safari suits and jumpsuits – and remaking them for women.

Examples of creations by Yves Saint Laurent, displayed at the new museum. Photograph: Stephane de Sakutin/AFP/Getty Images

“I had noticed men were much more confident in their clothes,” said Saint Laurent, who died in 2008, in a rare interview. “So I sought through trouser suits, trench coats, tuxedos and pea coats to give women the same confidence.”

His black tuxedo for women, known as le smoking – often worn over bare flesh – caused a scandal in 1966, with the New York socialite Nan Kempner dropping her trousers when she was told by a Manhattan restaurant that women would not be admitted in such attire.

Saint Laurent would later design a jacket as a thigh-skimming mini dress just as Kempner, one of his best customers, had worn it.

The heart of the Paris museum is Saint Laurent’s studio, the inner sanctum where he would work night and day in the run-up to his shows. It remains just as he left it in 2002, his desk festooned with photos of his inner circle of glamorous female friends, including Catherine Deneuve, Bianca Jagger and Paloma Picasso. But pride of place goes to a New Year’s card he made from a painting by his friend Andy Warhol of his French bulldog Moujik.

One wall of the room is completely mirrored, which allowed Saint Laurent to work directly on his live models so he could see his creations from all angles as they progressed.

Desk and utensils used by Yves Saint Laurent. Photograph: Yoan Valat/EPA

The museum offers insight into Saint Laurent’s creative process, showing how he developed his clothes from basic sketches into complex designs that, in the case of some of his haute couture creations, could take thousands of hours to make.

“Unlike many other designers, Saint Laurent began systematically archiving his work in the early 1960s – encouraged by Bergé – and so we can follow the evolution of each item,” said a spokesman for the museum, which holds 5,000 prototypes for his creations.

Other rooms in the museum are given over to Saint Laurent’s inspiration and the “imaginary voyages” his collections often took to Asia, Africa and most famously Russia. But other than his sojourns in Morocco – which reminded him of Algeria, where he was born in 1936 when it was a French colony – the designer was not much of a traveller.

With Bergé he built up a considerable art collection and he borrowed liberally from artists such as Pablo Picasso, Henri Matisse and Vincent van Gogh, most famously with his Mondrian dress, which became an instant pop icon when it hit the catwalk in 1965.

Cocktail dress (C) designed in homage to the artist Piet Mondrian. Photograph: Oli Scarff/AFP/Getty Images

Bergé always believed that Saint Laurent, who began his career by stepping into the shoes of Christian Dior when he was 21, was nothing less than an exceptional artist, calling him “the greatest designer of the second half of the 20th century”.

Having “spent all my life helping Yves Saint Laurent build his work, which I want to last”, Bergé died this month before he could see the museums opened. The American landscape artist Madison Cox, whom Bergé married this summer, told AFP that “10 days before he died he told me that ‘I am going to die totally at peace’, and I think that was true. He was a very determined man and he had put everything in place.”

Cox said the museums were also a tribute to Bergé’s work supporting and protecting the fragile Saint Laurent, who had drink and drug addictions.

“Of course I and the whole team are profoundly sad that he will not be here,” said Cox, who now heads the charitable foundation. “But he would have wanted that we go on.”