Princess Eugenie requested her wedding dress be designed with a low back as a tribute to the hospital where she had a childhood operation for scoliosis.
The dress, designed by by British-based Peter Pilotto and Christopher De Vos, features a neckline that folds around the shoulders to a low back that drapes into a flowing full length train.
The low back feature was specifically requested by Eugenie, who had surgery aged 12 to correct scoliosis, Buckingham Palace said.
The princess has spoken of the importance of showing "people your scars."
Eugenie was diagnosed with scoliosis when she was 12 years old and received treatment at the Royal National Orthopaedic Hospital (RNOH), undergoing a successful operation to straighten her spine.
The Queen's granddaughter invited representatives from the RNOH NHS Trust to attend her wedding to Jack Brooksbank on Friday.
The couple tied the knot at St George's Chapel in Windsor Castle, with members of the public and charity representatives on the guest list for the grounds.
Ahead of her big day, the royal reflected on the surgery and the importance of the charity.
"I'm patron of their appeal and I had an operation when I was 12 on my back, and you'll see on Friday, but it's a lovely way to honour the people who looked after me and a way of standing up for young people who also go through this," she told British TV.
"I think you can change the way beauty is, and you can show people your scars and I think it's really special to stand up for that.
"So that's one really important one.
"But separate to that, other organisations that are there, it's just very important that they get a chance to be honoured for the work that they do constantly, so it's lovely that I can share this special day with them."