But all the while, she felt there was room to grow in menswear. Unlike with other big fashion houses, where womenswear is the more lucrative machine, Givenchy's business is “50–50” she told me. And since her spring 2018 couture debut, which provocatively included men's clothes, a buzz had been building. Suddenly, she said, there were “all these A-list actors and musicians immediately wanting to come to the house and order and really wear this idea of a more flamboyant man, but with a strong structure to it, a strong sense of tailoring.”

Waight Keller's menswear doesn't look girlish—rather, it looks louche, luxurious, and even flirtatious.

She knew she could push the vision further—that as a menswear designer, she had more things to say. So in January she held a confident but understated presentation—fluid, glam tailoring and sportswear, with a sense of unplaceable retro—during Paris Men's Fashion Week. The excitement she was generating amplified in the spring, when Givenchy announced its massive show at the menswear-only mecca Pitti Uomo.

Though the show was now only two days away, Waight Keller seemed anarchically calm. Given the duties she juggles, Waight Keller might be the hardest-working designer in fashion. But you wouldn't know it, either from her presence on Instagram, a place where fashion-industry people love to share footage of themselves flinging around the world in pursuit of the next exotic #inspo, or from her demeanor. She radiates calm and approachability—a striking contrast to the French couturier archetype (usually: angry, and a man). I asked her how she balances all these collections, many of which require simultaneous work and separate visions, and she said simply, “I'm organized!”

One would have to be to handle just her growing responsibilities in menswear, a fashion category that suddenly finds itself at the center of the industry's attention. Within LVMH, the conglomerate that owns Givenchy, menswear has become a major focus: Louis Vuitton, Dior, and Berluti all appointed new menswear designers in 2018. The star power in particular of Dior's Kim Jones and Vuitton's Virgil Abloh—not to mention that of their supporters and friends, including A-list models and musicians—has brought a new level of excitement to men's clothing and the attendant fashion weeks, especially in Paris.

“This is why I'm moving towards men's shows, because I think it now really warrants it,” Waight Keller told me, excited about the possibilities for menswear to become as much an obsession—even a lifestyle—every bit as grand and glamorous as womenswear. “I want to start moving the menswear up to that level,” she said. I ask her about the show in a couple of days and about the message she wants it to convey. “It's the independent vision of menswear,” she said simply, like it's no big deal.

Many designers borrow from menswear in their womenswear, but Waight Keller does the opposite, blending the fantasy of women’s with the tailoring ingenuity of men’s

Waight Keller has a way of making the remarkable seem understated—sensible, even. This includes her own arrival at Givenchy, in 2017, which was greeted as a major moment in fashion's recent feminist wave. For over a century, the great irony of the Paris ateliers was that while they were the world's premier manufacturers of female fashion fantasies, they were mostly led by men.

With the exception of Elsa Schiaparelli and Coco Chanel, all the great couturiers of the so-called golden age—a period that stretched from just after World War II through the late 1950s—were men. Hubert de Givenchy, Cristóbal Balenciaga, Christian Dior, and Pierre Balmain. As time marched on, those eponymous couturiers were replaced with more men.

That narrative began to change when, in 2016, Maria Grazia Chiuri was appointed artistic director of Dior, overseeing womenswear, and when, a year later, LVMH announced Waight Keller as the new artistic director of Givenchy.

She stepped into the role after spending six years at Chloé, a brand that is the flirtatious embodiment of the French woman—all flounce and bohemia. There the silhouettes she perfected derived from a draping technique called flou, of which Waight Keller is a modern master. Despite her feminine bona fides, her résumé had, up to that point, swung between menswear and womenswear: She designed womenswear for Calvin Klein, served as the head men's designer for Ralph Lauren's Purple Label, oversaw womenswear at Gucci under Tom Ford, and spent the early years of the 21st century making men's and women's clothes at Pringle of Scotland, a once modest knitwear company that she helped grow into a global luxury brand.