On the evening of 29 June 1994, Princess Diana stepped out of a car outside the Serpentine Gallery in London and walked straight into history. She was wearing a figure-hugging, off-the-shoulder black silk dress by Greek designer Christina Stambolian – and within hours, the image had travelled around the world.

Now known universally as the “Revenge Dress,” the gown will return to the spotlight at Sotheby’s New York on 9 December, with an estimate of US$150,000–300,000. It will be exhibited first at Sotheby’s London from 18 September during London Fashion Week, before travelling to Hong Kong and Geneva, and arriving in New York on 2 December ahead of the sale.

Princess Diana’s “Revenge Dress” will go under the hammer at Sotheby's New York in December

That same evening, Prince Charles, as he then was, was due to admit to marital infidelity in a nationally televised interview. Diana had been separated from him for nearly two years, and speculation about the collapse of their marriage had dominated the British press for months. Details of the interview had leaked before the broadcast, so by the time the programme aired, the country was waiting to see what Diana would do.

She kept her commitment to the Vanity Fair fundraising dinner at the Serpentine. But at the last moment, she set aside the safer Valentino gown she had planned to wear and reached instead for the Stambolian dress, which had sat unworn in her wardrobe for three years – she had always considered it too daring. Her stylist Anna Harvey later recalled that Diana said she wanted to look a million dollars.

The black silk dress was made for Princess Diana by Greek designer Christina Stambolian

She stepped out to a wall of flashbulbs. Short, strapless and body-conscious, the dress was a pointed departure from royal convention. Worn with black heels, red nail polish, a clutch bag, and a dramatic sapphire-and-diamond choker – created from an antique brooch given to her as a wedding gift by the Queen Mother – it seemed to send Diana’s response to the world.

By the next morning, the front pages belonged not to Charles’s confession, but to Diana. The phrase “revenge dress” was coined almost overnight, and the cocktail dress became one of the most recognisable fashion statements of the late twentieth century.

The dress last appeared at auction in June 1997, when Diana – at the suggestion of her son Prince William – sold 79 gowns from her wardrobe at Christie’s New York to raise funds for cancer and AIDS charities. The Stambolian dress fetched £39,098 and was bought by a Scottish couple. Two months later, Diana passed away in Paris.

It is now being consigned by the same family. Over the years, the dress was shown at a handful of charity events in Scotland, most recently at Paisley Museum, before disappearing from public view for nearly three decades.

The lot will also include a rare copy of the original 1997 Christie’s catalogue, numbered and signed by both Diana and Stambolian, which credits Prince William with the idea for the sale. Part of the proceeds from the Sotheby’s auction will be donated to NHS Lothian Charity on behalf of the Royal Edinburgh Hospital.