“Every inch of this beautifully sculpted gown – a Christina Stambolian black cocktail piece, with a daring neckline and chiffon train – has been analysed for decades as the outfit Diana wore to knock Prince Charles off the front pages, just as he was about to broadcast his infidelity on television to the world.

“However, while this worked remarkably well – The Sun ran a photo of Diana in the ‘revenge dress’, with the headline: ‘The Thrilla he Left to woo Camilla’, this dress is about so much more than that.

“Princess Diana loved the dress but had resisted wearing it for three years because she was concerned it was too risqué for her position as the wife of Prince Charles within the Royal Family.

“Now, on the night of her husband’s revelation of infidelity, she wore the dress to celebrate who she really was, and what she really liked.