Princess Diana's dress was era-defining and shaped the careers of designers Elizabeth and David Emanuel, ITV News Correspondent John Ray reportS
The dress that Princess Diana wore on her wedding day in 1981 is going on display for the first time in 25 years.
The gown, one of the most recognisable in the world, will be on show at Kensington Palace from Thursday, less than a month before the princess' 60th birthday on July 1.
Diana's children, the Duke of Cambridge and the Duke of Sussex, have loaned the gown to the London exhibition, Royal Style in the Making.
The dress will be complete with its 25ft sequin-encrusted train, which dramatically filled the aisle of St Paul's Cathedral in July 1981.
Claudia Acott Williams, Kensington Palace curator, described it as the longest dress train in Royal history, saying it "definitely made a big visual statement".
Kensington Palace curator Claudia Acott Williams runs through the detail in Princess Diana's wedding dress
It features a fitted bodice overlaid at the centre both front and back with panels of antique Carrickmacross lace that had originally belonged to Queen Mary.
It also has a scooped neckline and large puffed sleeves that are trimmed with bows and deep ruffles of taffeta – a style which was made popular by Diana in the early 1980s.
Designers David and Elizabeth Emanuel also crafted a full skirt for the dress that is supported on a mountain of stiff net petticoats.
The curator said designers David and Elizabeth Emanuel "were very aware that this dress was going to be showcased against the backdrop of St Paul's Cathedral, which is in itself a monumental building and that the first view that onlookers would have and television cameras would have would be of her walking up the steps and into the building.
"So they designed this 25ft-long train to make a visual impact and before the wedding, they'd gone and they'd measured the width of the nave so they knew exactly what kind of space they needed to fill.
"And then we've got this wonderful, quite dramatic 80s silhouette to make sure that she was really visible."
Speaking about other details in the dress, she said: "The lace around the necklane and in the sleeves belong to Queen Mary and it was that lace that inspired all the other detailing of the dress. So they had new lace woven for the train and for the detailing in the skirt and all of that is lifted from that lace belonging to Queen Mary.
ITV News spoke to one of the designers behind Diana's dress, David Emanuel
"Also people are often surprised by just how dark the silk is and that's a reference to Queen Victoria's wedding dress - of course, the first Royal bride to wear white and it's all to wear ivory and this is an ivory rather than a white dress."
She continued: "So we've got something old in Queen Mary's lace, and there's something blue, a little piece of blue ribbon which is sewn into the back of the bodice, and also a little gold horseshoe, which is there as a little good luck symbol sewn into the back of the skirt."
The dress that Diana wore when she married “is now among the most famous in bridal history”, organisers say.
The exhibition opens to the public on June 3 and continues to the new year.
It also features Princess Diana's going away dress that she wore as she set off on her honeymoon, a pink dress designed by David Sassoon.
Ms Williams spoke of how designers saw the princess as "warm and friendly". Diana frequently corresponded with designers, giving them thank you notes and feedback to design tweaks. Some of these letters will be on display for visitors.
She said: "Diana was definitely involved in the creation of these garments, but I think her real strength was in choosing designers that really understood their craft, understood that her clothing needed to perform specific functions and convey particular messages.
Princess Diana regularly corresponded with designers, giving them thank you notes and feedback to design tweaks
"She was involved and she often sent feedback to them, but they all seemed to say that, by and large, she left them to get on with it and she trusted their style and their vision."
Ms Williams added: "Diana, Princess of Wales, is such an important figure in the history of Kensington Palace so we really wanted to do something to mark her 60th birthday and it seemed an appropriate moment, especially after months of lockdown."
A rare surviving toile for the 1937 coronation gown of Queen Elizabeth the Queen Mother, consort of King George VI, is among the other items of royal fashion history which are going on display.
Original sketches, fabric swatches and unseen photographs from the royal ceremonial dress collection will also be displayed to try to bring to life the skills that couturiers added to the royal wardrobe.
An array of glittering gowns and stylish tailoring which have been created for three generations of royal women is also billed to be among the items on show at the Kensington Palace Orangery.
Listen to The Royal Rota podcast: