Princess Diana had a second wedding dress she didn't even know about

In July of 1981, Lady Diana Spencer became Princess Diana when she married Prince Charles. 

And from that day on, Charles and Diana's royal wedding has become one of the most iconic days in history. Diana's wedding dress has been a known source of bridal inspiration for years, so it may come as shock to hear that she actually had a backup dress waiting for her. 

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Princess Diana
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LONDON - JULY 29: Diana, Princess of Wales and Prince Charles ride in a carriage after their wedding at St. Paul's Cathedral July 29, 1981 in London, England. (Photo by Anwar Hussein/WireImage)
Princess Diana (L), Prince Harry, (2nd L) Prince William (2nd R) and Prince Charles (R) gather for the commemorations of VJ Day, 19 August 1995 in London. Prince William turned 25 Thursday 21 June 2007, and in doing so became entitled to part of the multi-million pound (euro, dollar) inheritance left to him by his late mother, princess Diana. The second in line to the throne is now allowed access to the income accrued on the 6,5 million pounds he was left in his mother's will after she died 10 years ago in a car crash in Paris. AFP PHOTO/JOHNNY EGGITT/ (Photo credit should read JOHNNY EGGITT/AFP/Getty Images)
LONDON, ENGLAND: Royal Wedding. Photo of Diana Princess of Wales and Prince Charles taken by Boris Spremo July 29, 1981. (Boris Spremo/Toronto Star via Getty Images)
LONDON, ENGLAND: Royal Wedding. Photo Of Diana Princess of Wales taken by Boris Spremo July 29, 1981. (Boris Spremo/Toronto Star via Getty Images)
LONDON - JULY 29: Prince Charles, Prince of Wales and Princess Diana, Princess of Wales, kiss on the balcony of Buckingham Palace following their wedding on July 29, 1981 in London, England. (Photo by Anwar Hussein/WireImage)
LONDON, ENGLAND: Royal Wedding. Photo of Diana Princess of Wales and Prince Charles taken by Boris Spremo July 29, 1981. (Boris Spremo/Toronto Star via Getty Images)
LONDON, ENGLAND: Royal Wedding. Photo of wedding party showing Princess (Lady) Diana, Prince Charles, Queen Elizabeth II and Prince Philip, taken by Boris Spremo July 29, 1981. (Boris Spremo/Toronto Star via Getty Images)
ENGLAND - JULY 29: Diana, Princess of Wales is led down the aisle of St. Paul's Cathedral by her proud father, Earl Spencer, on her wedding day 29 July, 1981. (Photo by Anwar Hussein/WireImage)
PHILADELPHIA - OCTOBER 1: Princess Diana's wedding gown is displayed at a preview of the traveling 'Diana: A Celebration' exhibit at the National Constitution Center on October 1, 2009 in Philadelphia, Pennsylvania. The exhibit, not shown in the U.S. since 2007, opens tomorrow and continues through December 31. (Photo by William Thomas Cain/Getty Images)
(FILES) Picture dated 29 July 1981 of Diana, Princess of Wales, in her wedding dress. Ten years after her death in a Paris tunnel on 31 August 1997, Princess Diana shows no sign of retreating into the shadows -- her most enduring legacy the ability, even now, to engage, capture and divide public opinion. AFP PHOTO/PA FILES UK OUT //TO GO WITH AFP STORY / PACKAGE BRITAIN-ROYALS-DIANA-10YEARS / GB-ROYAUTE-DIANA-10ANS (Photo credit should read -/AFP/Getty Images)
Charles, Prince of Wales, and bride, Lady Diana, wave the crowd in coach as they pass through Fleet Street after their wedding at St Paul's Cathedral, on July 29, 1981. AFP PHOTO (Photo credit should read ARCHIVE/AFP/Getty Images)
(FILES) Picture taken 27 January 1988 shows Princess of Wales Diana, during her visit to the Footscray Park in suburb of Melbourne. Mohamed Al Fayed, the father of Diana, princess of Wales' boyfriend Dodi Fayed, maintained that the couple were murdered, after an inquest jury on March 7, 2008 returned a verdict of unlawful killing. AFP PHOTO PATRICK RIVIERE (Photo credit should read PATRICK RIVIERE/AFP/Getty Images)
JANUARY 1988 - Princess Diana travels on the official train for the Bicentennial Royal Tour in Sydney, Australia. (Photo by Patrick Riviere/Getty Images)
PARIS, FRANCE - NOVEMBER 14: Picture dated 14 November 1992 of Princess Diana leaving the first anti-AIDS bookshop in Paris. Diana, Princess of Wales died in hospital early 31 August after a midnight car crash in central Paris in which her friend the Egyptian millionaire film-producer Dodi al-Fayed and driver were also killed. At the time of the crash, the car was being pursued by paparazzi press photographers on motorcycles. (Photo credit should read VINCENT AMALVY/AFP/Getty Images)
HONG KONG, HONG KONG: Britain's Princess Diana stands with tennis players Michael Chang of the US (L) and Sweden's Jonas Bjorkman during the awards ceremony at the Hong Kong Open 23 April. Princess Diana, on a private visit to Hong Kong, watched as Chang defeated Bjorkman 6-3, 6-1 to win the tournament. AFP PHOTO (Photo credit should read EMMANUEL DUNAND/AFP/Getty Images)
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David and Elizabeth Emanuel, the designers behind the famous gown, explained to People that they wanted to give themselves peace of mind by making a second wedding dress in case the design of the gown that Diana planned on wearing was revealed before the big day.

"At the time we wanted to make absolutely sure that the dress was a surprise... Had the secret of the real dress got out it’s possible that Diana would actually have worn this one,” said Emanuel. 

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Princess Diana Style Transformation
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Princess Diana Style Transformation
Lady Diana Spencer, later the wife of Prince Charles, on her first birthday at Park House, Sandringham.
A very young Diana in a fancy pram.
Lady Di at age 2.
Young Lady Diana in a buttoned up dark coat.
Lady Diana at age 8, wearing a matching dress and headband.
Diana on holiday with her family, causal in a sweater and jeans.
Diana let her hair grow long during her youth, here age 10 in a wide-brimmed black hat.
Diana always had a passion for children, here at 19 working as a Nursery Assistant at a Kindergarten school.
Diana and Charles pose on the day of their engagement, showing off her diamond and sapphire engagement ring.
Diana was stunning on her wedding day, with the most glamorous dress and bouquet -- truly fit for a Princess.
The royal couple during their honeymoon in Scotland.
Diana attended an exhibition at the Victoria and Albert Museum, in a dress designed by Bellville Sassoon.
Princess Diana, pregnant and glowing at a Polo match in Windsor.
The Prince and Princess visit Wales, Diana wearing a suede beret by John Boyd and a coatdress by Arabella Pollen.
Diana was a vision in yellow as she and Charles visited a school in Alice Springs, Australia.
We're loving the pops of pink in Diana's outfit, here while watching Charles play Polo.
Diana talks with Prince Charles, who is on horseback, at a Polo match.
Diana is pretty in pink while attending the ballet Swan Lake.
Diana and a tiny Prince William leaving the Royal Yacht, the Princess in a belted plaid jacket.
Diana laughs with Nancy Reagan, the two ladies looking radiant in hues of red and white.
Diana rests her chin in her hands on the steps of her home at Highgrove.
Diana at a desert picnic in Saudi Arabia, wearing a purple and white outfit by Catherine Walker.
Diana attended Cannes Film Festival, wearing a stunning ice blue gown by Catherine Walker.
Diana was stunning at an evening function during a visit to Germany, wearing a gown by Victor Edelstein.
Princess Diana during a visit to Melbourne.
Diana and Wills at a polo club, the Princess casually dressed in a blazer with the British Lung Foundation logo on the front of her t-shirt.
Diana looked radiant in red and purple while in Hong Kong, the outfit designed by Catherine Walker.
During her visit to Hong Kong, Diana wore this stunning tiara and white dress, later known as the "Elvis Dress."
The Princess of Wales in mint on an official visit to Hungary.
Diana and her boys, attending a church service.  Diana wore a pink and purple suit by Catherine Walker.
Diana wears her favorite designer once again, Catherine Walker, during an official visit in Brazil.
Diana wore this white dress and black jacket designed by Catherine Walker during a visit to Salisbury.
Diana was stunning at a banquet in Seoul, wearing the Spencer family tiara and a gown by Catherine Walker.
Diana looked lovely in this pastel suit, crouching down to speak with a young boy.
Lord Palumbo greets Princess Diana, wearing a short black cocktail dress designed by Christina Stambolian, as she atttends a gala.
Diana visited army barracks, wearing a Versace suit and a hat by Philip Somerville.
The Princess of Wales was gorgeous in this royal purple gown during a visit to Chicago.
Diana visited Washington, dazzling the entire country in this lovely white gown.
Diana was lovely in this pale blue cocktail dress by Catherine Walker, attending a charity reception.
Diana, Princess of Wales, was radiant in red during another visit to Washington, D.C.
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It also has been revealed that Princess Diana didn't know about the second dress or try it on. "We didn’t try it on Diana. We never even discussed it,” Emanuel added. 

Luckily for everyone involved, the wedding gown's design was not leaked before the big day. The original dress was worn down the aisle according to plan, and has since become a fixture in wedding dress history.

This past May, Meghan Markle became a duchess when she wed Prince Harry. And just like her sister-in-law, Kate Middleton, Meghan wore a second dress to her wedding reception. While Princess Diana's second dress has yet to be revealed, our fingers are crossed that we get a peek at this never-finished frock in the future.

See the best shots from Meghan and Harry's wedding below!

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The best photos from Meghan and Harry's royal wedding
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The best photos from Meghan and Harry's royal wedding

Prince Harry, Duke of Sussex and the Duchess of Sussex hold hands in the Ascot Landau Carriage as their carriage procession rides along the Long Walk, on May 19, 2018 after their wedding ceremony.

(Photo by Yui Mok - WPA Pool/Getty Images)

Britain's Prince Harry, Duke of Sussex and his wife Meghan, Duchess of Sussex emerge from the West Door of St George's Chapel, Windsor Castle, in Windsor, on May 19, 2018 after their wedding ceremony.

(Photo by Ben Birchall / POOL / AFP) 

Ms. Meghan Markle walks down the aisle at the start of her wedding to Prince Harry in St George's Chapel at Windsor Castle on May 19, 2018 in Windsor, England.

(Photo by Danny Lawson - WPA Pool/Getty Images)

Britain's Prince Harry, Duke of Sussex and his wife Meghan, Duchess of Sussex leave from the West Door of St George's Chapel, Windsor Castle, in Windsor on May 19, 2018 in Windsor, England.

(Photo by Ben STANSALL - WPA Pool/Getty Images)

The Duke and Duchess of Sussex on the steps of St George's Chapel at Windsor Castle following their wedding ceremony in St George's Chapel at Windsor Castle on May 19, 2018 in Windsor, England.

(Photo by Danny Lawson - WPA Pool/Getty Images)

Prince Harry, Duke of Sussex and The Duchess of Sussex leave St George's Chapel, Windsor Castle after their wedding ceremony on May 19, 2018 in Windsor, England.

(Photo by Andrew Matthews - WPA Pool/Getty Images)

Princess Charlotte sticks out her tongue as she rides in a car to the wedding of Prince Harry and Meghan Markle at St George's Chapel in Windsor Castle on May 19, 2018 in Windsor, England.

(Photo by Andrew Milligan - WPA/Getty Images)

Britain's Prince Harry, Duke of Sussex kisses his wife Meghan, Duchess of Sussex as they leave from the West Door of St George's Chapel, Windsor Castle, in Windsor, on May 19, 2018 after their wedding ceremony.

(Photo by Danny Lawson / POOL / AFP)

Britain's Prince Harry, Duke of Sussex and his wife Meghan, Duchess of Sussex wave from the Ascot Landau Carriage during their carriage procession on Castle Hill outside Windsor Castle in Windsor, on May 19, 2018 after their wedding ceremony.

(Photo by Paul ELLIS / POOL / AFP) 

US actress Meghan Markle, accompanied by Britain's Prince Charles, Prince of Wales walks down the aisle toward her husband-to-be Britain's Prince Harry, Duke of Sussex, in St George's Chapel, Windsor Castle, in Windsor, on May 19, 2018 during their wedding ceremony.

(Photo by Dominic Lipinski / POOL / AFP)

Meghan Markle and her mother, Doria Ragland, are driven along the Long Walk as they arrive for her wedding ceremony to marry Britain's Prince Harry, Duke of Sussex, at St George's Chapel, Windsor Castle, in Windsor, on May 19, 2018.

(Photo by EMMANUEL DUNAND / AFP) 

Prince Harry and Meghan Markle during their wedding service, conducted by the Archbishop of Canterbury Justin Welby in St George's Chapel at Windsor Castle on May 19, 2018 in Windsor, England.

(Photo by Dominic Lipinski - WPA Pool/Getty Images)

Princess Charlotte on the steps of St George's Chapel after the wedding of Prince Harry and Meghan Markle in St George's Chapel at Windsor Castle on May 19, 2018 in Windsor, England.

(Photo by Jane Barlow - WPA Pool/Getty Images)

Britain's Prince Harry, Duke of Sussex and his wife Meghan, Duchess of Sussex emerge from the West Door of St George's Chapel, Windsor Castle, in Windsor, on May 19, 2018 after their wedding ceremony.

(Photo by Ben STANSALL / POOL / AFP) 

Meghan Markle is driven to St George's Chapel in Windsor Castle along with her page boys Brian and John Mulroney at St George's Chapel at Windsor Castle before the wedding of Prince Harry to Meghan Markle on May 19, 2018 in Windsor, England.

(Photo by Toby Melville- WPA Pool/Getty Images)

Britain's Prince Harry, Duke of Sussex and Meghan Markle, Duchess of Sussex, stand together at the altar in St George's Chapel, Windsor Castle, in Windsor, on May 19, 2018 during their wedding ceremony.

(Photo by Dominic Lipinski / POOL / AFP)

Prince Harry, arrives with his best man Prince William, Duke of Cambridge for the wedding ceremony of Prince Harry and US actress Meghan Markle at St George's Chapel, Windsor Castle on May 19, 2018 in Windsor, England.

(Photo by Odd Anderson - WPA Pool/Getty Images)

Britain's Prince Harry, Duke of Sussex and his wife Meghan, Duchess of Sussex arrive back at Windsor Castle in the Ascot Landau Carriage after their wedding ceremony and after their procession in Windsor, on May 19, 2018.

(Photo by Steve Parsons / POOL / AFP)

Meghan Markle's mother Doria Ragland, Britain's Prince Charles, Prince of Wales and Britain's Camilla, Duchess of Cornwall leave the wedding ceremony of Britain's Prince Harry, Duke of Sussex and Meghan Markle.

(Photo by Ben STANSALL / POOL / AFP) 

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