The Givenchy dress, bought by an anonymous bidder, was one of a group of more than 40 Hepburn items offered by specialist auctioneer Kerry Taylor in association with Sotheby’s. Most of the items, dating from the 1950s and ‘60s, were entered by Tanja Star-Busmann, a lifelong friend of the Belgian-born actress. Hepburn regularly sent her boxes of unwanted clothes.

A turquoise cloche silk cocktail gown acquired by Hepburn from Givenchy’s 1966 autumn/winter collection was bought by a U.S.-based museum for 18,000 pounds, said Taylor in an e-mailed statement. It had been expected to sell for as much as 12,000 pounds.

The sale also included the bridal gown made in 1952 by the Fontana Sisters for Hepburn’s planned wedding to U.K. businessman James Hanson. At the time, the star was on location in Italy filming “Roman Holiday.” After the wedding was called off, the ivory satin dress was given by Hepburn to a young Italian, Amabile Altobella, for her marriage to a farm worker. Altobella was the seller.

The rediscovered gown, complete with a photograph of Hepburn wearing it, sold to a private collector for 13,800 pounds, beating a high estimate of 12,000 pounds.

The Hepburn lots achieved a total of 268,320 pounds, more than doubling the presale valuation of 100,000 pounds. All realized prices included 20 percent auction house fees.