Princess Diana was a 19-year-old in a simple sweater and skirt when she first walked into the London studio of the up-and-coming designers she would ultimately choose to make her landmark wedding dress.
Designer Elizabeth Emanuel recalls that the young bride-to-be morphed as the weeks elapsed before her 1981 wedding to Prince Charles, losing a notable amount of the “puppy fat” she had when she first walked in.
“Most brides do lose weight,” Emanuel tells PEOPLE. “So we weren’t that worried when she did. She was looking fantastic. She ended up with a 23-inch waist from a 26- to 27- inch.
“She just walked more confidently. She just was suddenly growing up, you know? But I think she felt very good about how she looked.”
When the then-Lady Diana Spencer first rang up the studio, Emanuel mistakenly got her name wrong. So it was a total surprise when the new fiancée of the future king strode in for their initial meeting. “There was instant recognition when she walked through the door,” she recalls.
Emanuel and her husband and designing partner at the time, David, created the voluminous gown in total secrecy. “She was just lovely, really kind of easy going,” she recalls of the low-key Diana. “We never had any special instructions about how to make the wedding dress. That added a bit to the fun of it all, made it bit of an adventure.”
Emanuel, who now runs her own fashion line, is among the friends and family (including Diana’s brother Charles, 9th Earl Spencer) and confidantes remembering the late princess in a two-night television event from PEOPLE and ABC, The Story of Diana, airing on ABC on Aug. 9 and 10 at 9 p.m. E.T.
The designing couple (who later split) decided to make Diana’s iconic bridal train as long as possible because “St. Paul’s Cathedral is a really big area to fill,” notes Emanuel.
The final fitting was in Buckingham Palace so they could test out the train in all its glory in a spectacular corridor. “This was a real royal palace. Here was Diana in our wedding dress which we designed for her,” says Emanuel.
On the big day, Diana wore jeans and watched TV while having her tiara added to her newly done hair in Clarence House, bridesmaid India Hicks recalls.
“She was incredibly together and wasn’t panicking,” says Emanuel. “But I was really worried about all things that could possibly go wrong. We’d taken smelling salts, glucose tablets — what if she feels faint? What if she passes out? Spills something down her skirt?”
“I had this kind of horror that maybe the train would drop off. We sewed her into things, we pinned her into things.”
When the big moment came on July 29, 1981, the dress cascaded out of the royal carriage, as Diana took her place alongside her proud father John, 8th Earl Spencer.
“It’s always been about a butterfly emerging from a chrysalis,” recalls Emanuel. “And that is her story, really. She was emerging into a new world, a new life’s adventure.”