The look became so iconic not just due to it turning heads but also the fact it was worn by Diana on the same evening Prince Charles confessed on national television that he had been unfaithful in their marriage.
"It is a deeply regrettable thing to happen, but it does happen, and unfortunately in this case, it has happened," Charles said in his televised confession.
Admitting to his affair with now-wife Camilla Parker-Bowles a year and a half after his split from Diana, Charles claimed he had been faithful in his marriage to Di, that is “until it became irretrievably broken down”.
WATCH: Prince Charles talks candidly about the break down of his marriage to Diana.
Diana’s choice of outfit for that evening was a very conscious decision.
"She decided that she was going to fight back, and she decided that she would chose a dress that she had previously rejected as being a little too much.
And she would put that on and go out on the town," William Ivey Long, costume designer for the Broadway musical Diana, told PEOPLE.
The infamous and stunning outfit, however, wasn’t Diana’s first choice.
It is reported Diana had originally planned on wearing a Valentino number to the gala, but a leak to the press spoiling her plans led the Princess to make a last-minute change, instead choosing the now iconic Christian Stambolian frock.
Diana sold the dress at a media auction to raise money for cancer and AIDS-related charities just three years later.