Kensington Palace, Princess Diana's former home is going to display the dress which she wore 40 years ago on her wedding day.
The dress has been loaned to the exhibition which is going to start one month prior her 60 birthday by the dukes of Cambridge and Sussex, reports BBC.
It was designed by David and Elizabeth Emanuel for the July 1981 wedding.
The gown features a 25ft (7.6m) sequin-encrusted train, which filled the aisle of St Paul's Cathedral.
Organisers of the exhibition, Royal Style in the Making, say the dress is "now among the most famous in bridal history".
The dress has a fitted bodice overlaid with panels of antique Carrickmacross lace originally belonging to Queen Mary.
As well as the nod to history, it was very much in keeping with early 1980s fashion with its large puffed sleeves trimmed with bows and deep ruffles of taffeta.
In a video shown at the exhibition, Ms Emanuel remembers Diana phoning to ask her and her then-husband to make her dress.
"It was one of those strange moments where you know your life is never going to be the same again," she said.
As well as their mother's wedding dress, Princes William and Harry have also loaned her going-away dresses to the show.
The exhibition, which looks at designing an outfit for a royal client and also features those who dressed the Queen, Princess Margaret and the Queen Mother, is being held at the Kensington Palace Orangery.
It opens to the public on 3 June and continues on to early January 2022.
It also features a rare surviving toile - an early version of a finished garment - for the 1937 gown worn by Queen Elizabeth the Queen Mother for King George VI's coronation.