Jackie Kennedy was 39 years old when she married Aristotle Onassis on October 20, 1968. One of the many pleasures of Valentino: Master of Couture, opening today at Somerset House in London, is the opportunity to reflect on how incongruously jeune fille her wedding dress was, with its lacy stockings and bowed, kitten-heeled shoes. It would look positively dreamy on Cara Delevingne, 2012′s Girl of the Year. That’s one way of making the point that, in the 50 years of Valentino outfits on display in Patrick Kinmonth, Antonio Monfreda, and Alistair O’Neill’s masterfully curated exhibition, there is virtually nothing that couldn’t walk down a street or—more likely—a red carpet today. Call it timeless genius, or maybe just settle for the fact that, in being true to his own vision, Valentino managed to glide past the whims of the moment. The curation makes that point crystal clear. “The clothes are grouped not by decade but by instinct,” Kinmonth explained at a preview yesterday, “because Valentino as a designer was always instinctive, never trend-driven.” Just check out the first look in the exhibition, from 1959. The navy blue wool cocktail dress with panel detailing on the back has got Alexa Chung written all over it. (Funny coincidence that Valentino was chosen to present her with the Style Icon trophy at the British Fashion Awards on Tuesday night.)

Kinmonth and Monfreda were responsible for Valentino’sfarewell to fashion in Rome in 2007, but where that event had an imperial grandeur, this one is intimate and reflective. Monfreda took one look at the long, vaulted space in Somerset House and imagined a catwalk where the “audience” was composed of mannequins wearing the clothes, and the “models” were the visitors. It’s a simple, brilliant switcheroo that transforms a tricky venue into le dernier cri in fashion exhibitions. No mean achievement given Kinmonth and Monfreda’s track recordwith the Met’s Costume Institute.

“All my girls, my daughters,” Valentino mused yesterday as he looked at his dresses. “I feel like the daddy.” But fathers have favorites and, pressed to pick a few, the designer indicated apink taffeta suit from 2008, a blue chiffon dress he’d first sketched in the fifties, a satin and lace evening dress that Doris Brynner wore to the Patino Ball in 1968. He chuckled over a camo-patterned couture gown from Fall 1994. “Warhol had done it in art, so I thought why not do it in fashion,” Val recalled. “Not one sold.”

There are, in fact, 45 dresses from the Valentino archives that have never been seen before, alongside more obvious drawcards like Julia Roberts’ Oscar dress, Jackie’s iconic ensemble and Princess Marie-Chantal of Greece’s wedding dress, which took 25 people four months to make, with every minute obvious in the surreally extravagant result. Adjacent to the M-C opulence is a room screening videos that detail the techniques that created the clothes. There is also a “virtual museum” (available soon online), which includes more “how-to’s” for obsessives who care to duplicate the extraordinary handwork on display throughout the show. The “behind-the-scenes” element is Kinmonth and Monfreda’s acknowledgement of London, a rather moreloosey-goosey proposition than Rome, the city that hosted the last Valentino retro they designed. But it also offers an intimate human perspective on the grand legacy that Giancarlo Giammetti, the éminence grise of the Valentino story, has worked so hard to guarantee. The designer himself seemed to be feeling the same thing. Asked what he wanted people to feel as they left the exhibition, his answer was a wistful, “We miss you.”

Plus: See all the photos and read Tim Blanks’ report from the exhibition’s celebration dinner here.