The king is dead; long live the king. Azzedine Alaïa’s heart failed last November, but his presence will be more keenly felt in Britain this year than ever before. A major exhibition opens at the Design Museum in May, with his first London boutique coming to New Bond Street before that. After the outpouring of emotion on his death – from Naomi Campbell, who lived with him as a teenage model and always called him Papa; from the Parisian great-and-good who ate couscous at his table; from the clients who worshipped how he made them look – 2018 will be the year when Alaïa is recognised not just as the man who changed what models wore, but as the man who changed what we all wore.

“For me, fashion is the body,” Alaïa said in 1982. The rest of us took a little while to catch up, but we certainly got there in the end. Since the mid-80s, the skin and curve and flesh and muscle of women’s bodies have been the beating heart of how we want to look, with the role of fabric being to enhance that. That was how Alaïa saw it from the start. “I make clothes, women make fashion,” he would say, or: “I am not a designer, I am a couturier.” What he was saying, every time, was that it was the body that mattered most.

Naomi Campbell wearing a skirt by Azzedine Alaia in 1989. Photograph: Patrick Demarchelier/Conde Nast via Getty Images

When I say the body, I mean sex, of course. People can get very pious, in a well-meaning way, talking about designers who have died. There have been many righteous eulogies about Alaïa staying up all night perfecting a sleeve, breathless tales of weddings delayed while he stitched the bridesmaids into their dresses, morality lectures about how close he came to giving up on his light-as-air honeycomb knit before he mastered the technique. All of which is laudable and historically significant but slightly misses the point, which is that Alaïa put modern erotica into fashion.

There is nothing new about clothes that mould a body into an hourglass – the earliest known corsets are the stiffened belts built to reduce waist size depicted on Minoan pottery in around 1500BC – yet Alaïa was revolutionary in the way he looked at women’s figures. Where corsetry created a static, airless ideal of a womanly shape, Alaïa worked with seams, stretch and drape to create a sex appeal that was raw and muscular. His bodies were shaped with muscles and with seams, not with whalebone and horsehair padding.

Alaïa with Grace Jones wearing a dress made for A View to a Kill. Photograph: Sharok Hatami/REX/Shutterstock

It is such a cliche to say of a male fashion designer that he “loved women”. Yet everyone says it about Alaïa, and it points to what separates him from the many other male designers who have fetishised the body. Growing up in Tunisia, his first apprenticeship was to a midwife with whom he helped deliver babies from the age of 10. Later, one of his early jobs in Paris was to create made-to-measure costumes for the G-stringed dancers at the Crazy Horse cabaret. (“From the Crazy Horse he learned the aesthetics of the entire body and the importance of the fesse – the backside,” says his long-term collaborator Caroline Fabre-Bazin.) Where other designers closet themselves in an atelier, sketching women in pencil and erasing at will, Alaïa – so often pictured smiling with an Amazonian beauty towering over him in one of his dresses – was unintimidated by flesh-and-blood women. “He put seams in very special places,” stylist turned architect Sophie Hicks says in Joe McKenna’s documentary about the designer. “He put seams around the buttocks, around the breasts, over the front of the ribs … this was someone who really understood how a woman’s body worked.”

There is no point rose-tinting the Alaïa legacy by painting him as accepting of all shapes and sizes. He fetishised a tiny waist, high breasts, exaggerated curves, long legs. The push-up bra shapes he introduced in the 80s paved the way for the Wonderbra. His point of view on the female body was celebratory and perfectionist at the same time. Yes, this is contradictory, but it is also an uncanny reflection of where we are right now in the conversation about women’s bodies. In case you are either of the two people in the world who has never seen Emily Ratajkowski’s social media posts, celebrating the awesomeness of women generally via celebrating your own gym-honed physical awesomeness is very 2018. “Azzedine loved women, and so he wanted them to be perfect,” his friend Carla Sozzani told me this weekend, ahead of Monday’s public opening of the first posthumous Alaïa exhibition at his Paris atelier. “I watched so many women try on an Alaïa dress and look in the mirror and be so happy that they had a waist. That made them smile and feel secure in their beauty – and then they looked even more beautiful.”

Alaïa’s pret a porter show, Paris 1991. Photograph: Guy Marineau/Conde Nast via Getty Images

Alaïa proposed a corporeal, powerful, animalistic ideal of female sexuality best symbolised by leopard print, which he brought roaring back into fashion with his autumn/winter 91/92 collection. Claudia Schiffer, Elle Macpherson and Naomi Campbell stalked that catwalk in dresses, leggings, lace-up stiletto boots, handbags, gloves and berets – all in leopard print. The impact on fashion was immediate and permanent: leopard print has never been out of style since. (The anthropomorphism of Alexander McQueen also owes something to Alaïa, who would sooner use an alligator skin whole, as the back panel of a coat, than snip it into trimmings.)

“You didn’t have to be skinny to wear his clothes,” says Sophia Neophitou, editor-in-chief of 10 Magazine and a close friend of Alaïa. “He liberated women like me, who have boobs and a bum, from being told we should wear tents all the time. And his clothes are so comfortable. I fly in his dresses, I watch my son play football in them. I’m a mother, I’m a wife, but I’m also a fashion editor and his clothes allow me to live my life without compromising what I want to project.” Bettina Graziani, the couture model after whom Givenchy’s Bettina blouse was named, wore Alaïa well into her 80s. Stylist Julia Restoin Roitfeld was one of many who wore his clothes while pregnant – Alaïa was a pioneer of clingy maternity wear, to show off what he said was the most beautiful curve of all.

The decade with which Alaïa is most closely associated with is the 80s: Grace Jones as a hooded Bond girl in A View to a Kill; Robert Palmer’s backing singers. Andy Warhol and Marisa Berenson turned up to Alaïa’s first New York show in 1982; Thierry Mugler stayed backstage, helping to dress the models. (“Fashionable, partygoing New Yorkers seem to have finally forsaken their midcalf culottes and prairie skirts in favour of a new interpretation of the high-heeled attitude of another era,” reported the New York Times.) But the exhibition in Paris, Je Suis Couturier, indicates no chronology for the 41 dresses. Each and every one could be worn in the front row of any of this week’s haute couture shows and not be overshadowed for a moment. Alaïa, after all, thought the system of biannual seasons was absurd and the notion of discarding a dress after a few months ludicrous. In which respect, once again, he was ahead of his time.