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.

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.

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!