A dress worn by Princess Diana at a party in London will be auctioned hours after a documentary was televised in which then-Prince Charles admitted to committing adultery during their marriage. Her dramatic arrival at the Serpentine Gallery in 1994 in a black silk evening dress custom-made by designer Christina Stambolian became an iconic pop culture moment. The media dubbed her outfit the “revenge dress.” Auction house Sotheby’s expects the dress to sell for up to $300,000 (£220,000) when it goes up for auction on December 9. A Sotheby’s news release said it is the first time the dress has been offered at auction since 1997, when the late princess sold 79 of her dresses to raise money for charity. Morgane Halimi, global head of handbags and fashion at Sotheby’s, said in a statement that Princess Diana “instinctively understood” that fashion can be a language in her “On her own terms, Princess Diana turned the dress into one of the most powerful messages she has ever given, during one of the most scrutinized and emotionally charged episodes of her life,” Halimi said. “She entered a time where much of her story was being told for her, and through what she chose to wear, she claimed the narrative for herself.”