PARIS.- In July 2022, just before the Balenciaga couture show, Didier Ludot returned from lunch to discover “the longest, most beautiful legs I have ever seen” at his namesake vintage couture boutique in the shopping arcades of the Palais-Royal. They belonged to Nicole Kidman, who was in Paris to walk in the Balenciaga show and was patiently waiting with her husband, Keith Urban.

They spent three hours browsing, with Urban fetching dresses for his wife, helping her to zip them up and then carefully replacing them on their hangers, prompting Ludot to jokingly offer him a post as his assistant. “They were a delight,” Ludot, 72, recalled recently.

It’s hard to imagine — now that every red carpet features a “vintage” dress or two, many only a few years old and now that the term has become something of a buzzword for sustainability — but when Ludot opened his door in 1974, he was the only boutique owner to curate his stock as if he were collecting couture for an art gallery. As much as anyone, he helped start the current phenomenon. And after 50 years, he has the stories to prove it.

He has always operated the boutique “like an art gallery, except we sell haute couture,” Ludot said. “Everything in the store belongs to me. There is no consignment, I buy every piece outright. It’s a galerie de la mode and I am its antique dealer. Next week, for instance, I have a rendezvous to view some Courrèges coats. If I like them and we agree on a price, madame will leave my boutique with her check.”

The same month that Kidman showed up, Julia Roberts arrived in the boutique with her two bulldogs. “I need a coat!” she told him through chattering teeth — it was an unusually cold summer. She left, he said, warmer and happier in an orange and green check Balenciaga.

“It makes me happy when my customer leaves wearing their acquisition,” Ludot said.

“I love to sell clothes that modern women can actually wear,” he said. “Of course I will buy a 1920s beaded Poiret gown, but that’s museum quality, too fragile to wear. It will be archived, laid flat, wrapped in tissue and protected from daylight. I prefer to see these beautiful pieces having a second life, worn again — the raison-d’être of a garment — admired again and cherished again. Because if vintage couture represents anything, it’s the embodiment of emotion.”

His boutique — now 125 square meters (1,345 square feet), triple its original size — is well known as a showcase for one of the finest collections of vintage couture in the world, a source not only for fashion lovers seeking distinctive pieces, but also for major fashion house designers, museum curators, design students and professional collectors.

Some of the notable celebrities who have found their way there, he said, include Kate Moss, Catherine Deneuve, Stephanie Seymour, Kate Winslet, Demi Moore, Sharon Stone, Lucy Liu, Sarah Paulson, Fan Bingbing, Joanna Lumley, Naomi Campbell and Kris Jenner.

Ludot said his favorite celebrity memory dates to 2006 and involves a 1956 Christian Dior ballgown in silver tulle, intricately embellished with swathes of satin and fabric roses — so exquisite that he had intended to keep it for his private collection.

He had just finished placing it in the boutique window when a group of Americans entered, asking its price. He told them it wasn’t for sale. When they politely insisted, saying they represented a Hollywood actress, he said 35,000 euros, or about $42,700 at the time. Unfazed, they made an appointment for a fitting.

The appointment was for Reese Witherspoon and Ludot and his husband, Félix Farrington, helped her into the fragile gown. She wore it to the 2006 Academy Awards, where she won best actress for her role as June Carter Cash in “Walk the Line.”

“This is the magic moment we live for!” Ludot said. “This couture ballgown was made to measure by Dior for an unknown woman. Fifty years later, another woman who wasn’t even born at the time, steps into the gown and it fits as if was made for her. It brought her luck, too, as she won an Oscar.”

As for designers, Karl Lagerfeld, Hubert de Givenchy, Marc Jacobs, Anthony Vaccarello, Pierpaolo Piccioli, Donatella Versace, John Galliano, Calvin Klein and Azzedine Alaïa have been among his regulars.

Hamish Bowles, Vogue’s global editor at large, is a frequent visitor, as is Miuccia Prada, who often arrived with Manuela Pavesi, her friend and colleague, until Pavesi’s death in 2015.

“Manuela Pavesi was the most stylish woman I have ever known,” Ludot said. “She’d arrive with diamonds in her hair wearing a fur coat over a pair of men’s pajamas and men’s Westons. She once bought some vinyl Courrèges pieces from me with crocodile skin print. At the next Prada catwalk collection, there they were!

“It’s not that they copy or imitate,” he added, referring to designers, “they inspire themselves with the best of what they find here.”

“Fashion has no memory,” said Serge Carreira, director of the emerging brands initiative at Fédération de la Haute Couture et de la Mode and a lecturer at Sciences Po Paris. “Didier Ludot’s brilliant curation gives us the time to examine fashion’s past.”

In 2010, Ludot was decorated with the Chevalier de l’Ordre des Arts et des Lettres, a lifetime achievement award for his fashion antiquarian work, presented by the French Ministry of Culture.

That expertise was evident before an auction of some of his private collection early last year as Ludot examined an Yves Saint Laurent lime green satin jacket, lavishly embroidered by Maison Lesage in a tribute to the French painter Pierre Bonnard.

He pointed out that the jacket had a bolduc d’atelier, or workshop tape, stitched to its interior. To the right of the YSL monogram printed on the tape was the name of Anne Fiona, the model who wore it on the catwalk, and to the left, the label AH88, indicating it was from the fall 1988 couture collection. Both were hand written in black ink.

“This shows that this is the designer’s prototype,” Ludot said. “It is the perfect execution of Monsieur Saint Laurent’s original vision. The proportions haven’t been adjusted to fit a client or modified in any way to her taste.”

He had estimated that the piece would sell for around 30,000 euros; it went for 34,112 euros.

It’s not the age of a piece that qualifies it as “vintage,” he said, it is its singularity, the defining look in a collection that reveals what he described as “the folly and fantasy” of the creator. Some of his choice examples: “Rick Owens’ 2015 Sphinx collection. Or Jean Paul Gaultier’s 2005 electric blue haute couture African Mask dress, with its Madame Grès-inspired bodice pleating.”

On Feb. 25, to mark his 50-year anniversary at the Palais-Royal, Ludot plans to debut a weeklong retrospective, displaying emblematic pieces by Cristóbal Balenciaga, Karl Lagerfeld for Chanel and Pierre Cardin and Yves Saint Laurent for Christian Dior, alongside contemporary creations from Stéphane Rolland’s fall 2023 couture collection, in homage to Maria Callas.

Ludot said he invited the independent French couturier to be the exhibition’s guest of honor because “Stéphane Rolland’s architectural creations reassure me and give me hope that haute couture can survive.” In that sense, he continued, they are the vintage of the future.

This article originally appeared in The New York Times.