One of the most famous fashion items in history, Princess Diana 's wedding dress is still iconic, even for people who were born years after she walked down the aisle.

When Di, 20 at the time, stepped out of her carriage and walked up the steps of St Paul's Cathedral, the world was in awe.

The antique lace and ivory silk taffeta gown featured more than 10,000 pearls and a long train.

However, there was one person who wasn't happy when she saw the dress on the wedding day - the women who designed it.

Elizabeth Emanual and her husband spent months creating the royal wedding dress, and ensured to keep the design a secret, reports The Mirror.

The creasing of the dress left the designer 'horrified' when she saw it
The creasing of the dress left the designer 'horrified' when she saw it

Speaking during ITV's Invitation to the Royal Wedding, Elizabeth admitted being horrified when she saw how creased Diana's dress had become in the journey.

She said: "We did know it would crease a bit but when I saw her arrive at St Paul's and we saw the creasing I actually felt faint.

"I was horrified, really, because it was quite a lot of creasing.

"It was a lot more than we thought."

They had completed a dress rehearsal but used a different material and it wasn't as bad.

But she now says, that looking back, the moment was actually her favourite shot of the Princess in the dress.

She compared it to a caterpillar coming out of a cocoon and becoming a butterfly.

Princess Di never saw the second dress because the original design was never leaked
Princess Di never saw the second dress because the original design was never leaked

A second, back up dress, was created in secret incase the main one was leaked.

David told People  :"At the time we wanted to make absolutely sure that the dress was a surprise.

"We didn’t try it on Diana. We never even discussed it. We wanted to make sure that we had something there; it was for our own peace of mind, really."

Diana never saw the second option, which was crafted from the same fabric as the first and featured ruffles around the neck, similar to the one she wore

British fashion designers David and Elizabeth Emanuel created the iconic gown
British fashion designers David and Elizabeth Emanuel created the iconic gown

The secret dress was a lot less lavish, without the antique lace and 10,000 mother-of-pearl sequins, as well as the 25-foot train.

It was also never fully completed because the original creation wasn't leaked.

Diana, standing at 5ft 10, was the same height as Charles and decided to wear low-heeled shoes on her wedding day so she wasn't taller than him.

The shoes, designed by celebrity shoemaker Clive Shilton, were made from satin, lace and more than 500 sequins and 100 pearls.

Princess Di also had the letters C and D painted on the suede soles with a small heart in between.

Prince Charles and Diana tied the knot at St Paul's Cathedral on July 29, 1981, after meeting only a handful of times.

They wed in front of 3,500 guests, including the royal family, celebrities and world leaders.

Around 750million people around the world watched the moment on TV.