The black evening dress worn by Princess Diana on the night her estranged husband, then-Prince Charles, now King Charles III, publicly acknowledged his infidelity is going up for auction for the first time.

The silk dress, designed by Christina Stambolian and widely known as Diana’s "revenge dress,” is expected to sell for between $150,000 and $300,000 at Sotheby’s in New York on Dec. 9, according to a press release.

Diana wore the dress to a fundraising dinner hosted by Vanity Fair at London’s Serpentine Gallery on June 29, 1994.

Her appearance came on the same evening that a nationally televised documentary aired in which Charles admitted that he had been unfaithful during their marriage.

The couple had been separated for nearly two years at the time.