Princess Diana’s wedding dress is one of the most recognized in history, and it’s full of tiny details and big secrets. See here for all the mysteries and some insights from the gown’s designer.

Wedding gown designer Elizabeth Emanuel tells all.

Three months before Princess Diana, then 20 years old, walked down the aisle to wed King Charles III, then a 32-year-old Prince of Wales, she called up Elizabeth Emanuel's small studio to ask if she would do her the honor of making her bridal gown. In that moment, the young designer was tasked with making a dress as singular as the People's Princess. She exceeded Diana and the world's expectations—creating what is the most recognized wedding dress of the last century.

Although utterly remarkable and inimitable, the frock inspired hundreds of copycat dresses and continues to capture brides' imagination to this day. From the moment Di stepped into St. Paul's Cathedral on July 29, 1981—for a union witnessed by hundreds of thousands of people—the gown became ubiquitous, but it wasn't always that way. To add to the centerpiece's allure, the public had no idea who was behind the dress or what it would look like, which deemed it the "most closely guarded secret in fashion history." And, this dress is chock full of secrets.

Ahead, we break down all the details and mysteries behind Diana’s wedding dress, some of which Emanuel herself revealed to InStyle. We caught up with the designer during the “Styling Princess Diana,” exhibit at Fotografiska on on May 21, 2024, held as part of People’s 50th anniversary celebration.

All the Details

Di's iconic wedding gown is a silk taffeta creation that was dyed an ivory hue, as opposed to a traditional crisp white. It features a frilly neckline, ruffled cuffs, puffed sleeves, a fitted bodice, a voluminous ballgown skirt, delicate lace detailing, intricate embroidery, 10,000 mother-of-pearl sequins, and, of course, a striking 25-foot train. The centerpiece was a family project, as it was designed by Emanuel and her former husband, David Emanuel; Elizabeth Emanuel's mom, Brahna Betty Weiner, also worked on the embroidery.

The Dress Broke Records

The 25-foot train is the longest in royal wedding dress history—a record the designers set out to exceed. “I always wanted to put the train with it. We spoke to Diana about it and had a bit of a laugh. We said, 'Let's make it longer than anybody else's train,'" Emanuel recalled. "And we looked it up, and by doing it 25 feet, it was longer than anybody else's. We had a lot of fun. It was a fun thing to do.”

The larger-than-life addition came with some hurdles, including having to be “folded like a bedsheet” in order to fit it into the carriage. Additionally, once the princess arrived at the cathedral, it took the designer duo and some of Di’s bridesmaids to straighten it out.

Even larger than the train was the bride's sparkly veil, which was a whopping 153 yards of tulle. The headpiece was hand-stitched by Peggy Umpleby of embroidery S. Lock (now called Hand & Lock) and decorated with 10,000 micro pearls. Emanuel fondly remembers it added a "magical radiance" to her fairytale frock.

The Emanuels Took Every Precaution to Keep the Dress Safe

Emanuel remembers her phone call with Di like it was yesterday. In addition to Diana's request for the Emanuels to make her dress, she also asked that it be kept a sworn secret. The Emanuels treated Di's plea with the utmost seriousness. They had two security guards, Jim and Burt, watch over the dress every night, locked the gown up in a metal cabinet, kept the shutters on their windows closed, and even put scraps of fabric in the garbage to throw journalists off their scent of what the dress looked like.

The Emanuels Received No Instructions From the Palace

Emanuel recalled having complete "free reign" when designing the dress—not a single guardrail or request from Buckingham Palace. From the get-go, they knew they "needed a big dress" to fill the grand space of St. Paul's Cathedral, and they "wanted it to stand out and look very different." But, above all, they wanted it to be something Diana "really loved."

“It was a fabulous time, the 80s. It was all about romance and frills…the style that we had at that time was very big skirts, ruffles, and all of that," Emanuel said. "When Diana came to see us, that’s what she really liked. The aim was to make a fairytale princess dress.”

The duo referenced books and historical photos, such as Queen Victoria's wedding dress, and drew up tons of sketches. However, their jumping-off point ended up being a dress Diana tried on from their sample range, which featured a cinched waist and puffy sleeves. Both the princess and the designers saw that style as the winning formula—from there, they set out to create a version that couldn't be copied.

Elizabeth Emanuel Nearly Fainted When She Saw Diana

And not in the way you’re thinking. Emanuel was "horrified" by the amount of creasing in the dress. She was expecting some, as is normal with taffeta, but not the resulting amount, which came from having to fold the train.

Diana Was Sewn Into the Dress

Over the 90-something days the Emanuels had to make the dress, Emanuel said Diana went from a 26/27 inch waist to a 23-inch waist. “We kept delaying cutting into the fabric because she kept losing the weight, and in the end, we just had to cut away. But we had to keep taking it in and taking it in,” she said during the Fotografiska panel. Ultimately, they had to sew Diana into the dress the morning of the wedding to ensure a perfect fit.

Emanuel shared they didn't see the dress "properly" until the wedding day at Buckingham Palace, as their studio was too small to extend the train all the way out.

There Was a Secret Back-Up Dress

The design duo prepped for every wedding disaster, including if the dress was stolen, set on fire, royally stained, or some other tragic accident. They even designed a secret backup dress, which differed from the one Diana wore down the aisle in that it had a bright white hue, fitted sleeves, and no train. It did, however, keep consistent with the original's frilly collar, ruffled cuffs, big skirt, fitted bodice, lace accents, and hand-stitched embroidery. Emanuel said they only finished it three-quarters of the way, as it felt "unlucky" to complete it; they just wanted to have something for their peace of mind. She also shared Diana had no idea it existed as they "didn't want to panic her" with the knowledge of a contingency plan.

After all the vows and kisses were exchanged, the Emanuels forgot about the backup dress, and one way or another, it vanished. However, Emanuel brought it back to life in 2024, creating a replica based on the “about 500 pictures” they took at the time.

Back in 1981, the duo also made a spare skirt for the original dress—and brought any and everything they could possibly need for the big day. “I took things like glucose tablets and safety pins and tissues," Emanuel remembered. "You name it, I had it in my bag just in case there was an emergency.”

As if their task wasn't ambitious enough, the designers also made the bridesmaid dresses.

Diana Stained the Bridal Gown

Diana’s wedding makeup artist Barbara Daly recounted the incident in her book Diana: The Portrait. She shared that while applying her favorite scent, Quelques Fleurs by Houbigant, Diana spilled the perfume on the skirt of her dress. Daly advised her to hold the stained spot while she walked, as to appear like she was not trying to step on it, but really to cover the blemish.

Good thing Emanuel planned for mishaps like that—except she had no idea it happened. “I didn't know anything about [the perfume stain]," she told InStyle. "They didn't tell me…I read about it.”

There Was Something Borrowed and Something Blue

Diana followed all the Victorian traditions on the day of her union. Her something old came in the form of a square of Carrickmacross lace that once belonged to Queen Mary; the rest of the lace was specially created in Nottingham to look like Queen Mary's lace. Meanwhile, her something new was the dress itself. Di's something borrowed was the Spencer Tiara, a family heirloom that featured diamonds shaped into tulips and stars and originally belonged to her grandmother, Lady Cynthia Hamilton.

Finally, her something blue was a little blue ribbon the Emanuels added to the waist of the dress, along with a small 18-carat gold horseshoe trinket sewn into the gown for good luck. Emanuel said the white diamond-studded charm was created by master jeweler Douglas Buchanan, who approached them with the idea.

“Every element was considered," Emanuel said. "We tried to get everything British, as well. Even the silk for the veil…they managed to squeeze a bit of British silk into it. There weren't enough butterflies to do the whole thing, but we got some in the silk veil."

Diana's Accessories Were Just as Fantastical

The princess was, of course, adorned with her gorgeous sapphire engagement ring. To add to her allure, she wore diamond earrings that had a pearl-shaped diamond in the center and 50 smaller ones surrounding it that came from her mother, Frances Shand Kydd. Her magical Cinderella slippers were created by cobbler Clive Shilton; like her dress, they were also ivory and featured a heart design on the toe, 542 sequins, 132 pearls, a painted C and D with a heart just below the heel (for, you guessed it, "Charles" and "Diana"), lace floral appliqués, and a low heel (so she wouldn't tower over the groom). For a last touch, she carried a bouquet of gardenia, stephanotis, odontoglossum orchid, lily of the valley, Earl Mountbatten rose, freesia, veronica, ivy, myrtle, and tradescantia flowers.

Once again, the ever-prepared Emanuels thought of everything: Emanuel said they created a matching parasol in case it rained.

Diana Left Her Wedding Gown to Her Sons

After the royal couple exchanged their vows, the dress took a global tour, making appearances in museums and exhibitions around the world. In 2014, per Diana’s will, it was passed down to Prince William and Prince Harry, following Harry’s 30th birthday, according to People.