If you fail to plan, you plan to fail. And there’s no way that designer Elizabeth Emanuel was going to let herself fail when she was asked to design a wedding dress for 20-year-old Diana Spencer in advance of her 1981 wedding to the then-Prince Charles.

“I was a bit neurotic, and I thought, ‘What happens if somebody breaks in and steals the dress or something spills or there’s a fire or it gets stolen?’” Emanuel told People about her own pre-wedding jitters 43 years ago. “So I thought, ‘I’m gonna make a backup dress.’”

And that’s exactly what she and her now ex-husband David Emanuel did, designing and then beginning to construct a dress that differed hugely from Diana’s now-iconic ivory gown, with its 25-foot train and veil-and-tiara combo.

“I just thought, ‘If anything happens, we’ll finish it off and have it ready,’” Elizabeth said of the dress, which featured fitted sleeves with frilled cuffs, and left off both the intricate hand-embroidered embellishments and cathedral train that the final dress featured. It was also a truer white than Diana’s ivory gown. “It likely ended up on some sample rail,” Elizabeth said of the unfinished contingency dress. “It probably got reused, torn up, thrown out, who knows?”

Now, using old sketches and thumbnails the designer has brought the dress that never was to life. It will be on display at the virtual interactive Princess Diana Museum.

Renae Plant, the museum’s director and curator, told the outlet why she sought the artifact out.

“We never got to see that dress on Diana and thought it would be lovely to envision it,” she said of the design. “You cannot put a price tag on history.”

Decades after the wedding, the couple's divorce in 1996, and Diana’s death, the appetite for anything related to Diana’s wedding has never waned. In 2022, a four-decade-old piece of fruitcake saved from the celebrations was even put up for auction.

Elizabeth Emanuel now recalls the moments before the wedding with fondness.

“We could hear the people outside cheering,” she said. “Everybody was happy and smiling. It really was a fairy-tale wedding.”