On This Day in 1994: Diana in her 'revenge dress'

Twenty-five years ago, the Princess of Wales stepped out in her "revenge dress".

It was June 29 1994 and the night the Prince of Wales, in a television interview, admitted he had been unfaithful to Diana.

The same evening, Diana appeared at the Serpentine Gallery in London's Hyde Park in what was dubbed her "revenge dress" – a figure-hugging, low-cut, off-the-shoulder little black dress, paired with a choker and pearl earrings.

Greek fashion designer Christina Stambolian revealed that the princess initially thought it was "too daring" and only opted for it at the last minute.

The Duke of Cambridge and the Duke of Sussex's mother – who died in a car crash in 1997 – was at the star-studded gala dinner as patron of the gallery and joined guests including actress Joan Collins and American actor Steve Martin.

She breezed in, full of confidence in the summer sunshine, smiling broadly as she greeted guests.

Meanwhile, 20 million viewers watched as Charles, in Jonathan Dimbleby's documentary Charles, The Private Man, The Public Role, told of his relationship with Camilla Parker Bowles, now the Duchess of Cornwall.

He said he had been faithful to Diana "until (their relationship) became irretrievably broken down, us both having tried".

He continued: "Mrs Parker Bowles is a great friend of mine ... a friend for a very long time."

The interview was aired just two days before Charles was due to mark the 25th anniversary of his investiture as the Prince of Wales.

The heir to the throne is celebrating the 50th anniversary of his investiture on Monday.

Diana and Charles separated in 1992, but finally divorced in 1996, a year before the princess was killed in a crash in Paris.