Netflix still has yet to reveal a release date for the third season of The Crown, but fans of royal origin stories can now tide themselves over with a visit to the Victoria and Albert Museum in London. This weekend marks the opening of the "Christian Dior: Designer of Dreams" exhibition at the museum, showcasing several of Dior's most iconic designs, including Princess Margaret's gorgeous 21st birthday gown, on loan from the Museum of London after undergoing a restoration.

The cream-colored silk gown, which Queen Elizabeth's younger sister wore on her milestone birthday in 1951, is the centerpiece of the exhibit. It features a full skirt, impossibly tiny belted waist, off-the-shoulder chiffon sleeves, and gold embroidery detailing across the front of the skirt and bodice. Margaret wore the dress to her birthday celebration and in her official birthday portrait, photographed by Cecil Beaton, and reportedly later referred to the dreamy confection as "my favorite dress of all."

Margaret maintained a strong relationship with Dior throughout her life. According to AnOther magazine, she first met the designer during a trip to Paris in 1949, after which he traveled to London to show his latest designs to Margaret and her sister. Margaret was a regular attendee at Dior's fashion shows, and presented him with an honorary membership to the British Red Cross in 1954. And the admiration went both ways: "She crystallized the whole popular frantic interest in royalty," Dior reportedly wrote of Margaret in his autobiography, Dior by Dior. "She was a real fairy-tale princess, delicate, graceful, exquisite."

Rounding out the "Designer of Dreams" exhibit—open to the public at the V&A through July 14—are more than 200 other haute couture designs, plus hundreds of other Dior-related mementos like accessories, photos, vintage perfumes and makeup, illustrations, magazines, and some of Dior's personal belongings. The exhibit traces not only Dior's own work, but the ways in which his successors as creative director of the French fashion house—Yves Saint Laurent, Marc Bohan, Gianfranco Ferré, John Galliano, Raf Simons, and Maria Grazia Chiuri, chronologically—have continued to carry out his legacy. (Bill Gaytten took over for about a year between Galliano and Simons, but, perhaps due to the lightning-fast nature of his role, is not represented in the exhibition.)

Unfortunately, we'll never know what Princess Margaret thinks of her favorite designer's being honored so extensively in her hometown—but perhaps Helena Bonham Carter, who will play the royal in the next season of The Crown, can strike up yet another conversation with Margaret's ghost and ask.

Related: Princess Margaret's Morning Routine Proves She Was Really a Queen