The former monarch allegedly said the tiara, which is one of the most expensive in the royal collection, was tied to controversy.

Meghan Markle’s royal wedding look evoked understated elegance, yet the tiara that she wore, Queen Mary’s Diamond Bandeau Tiara, gave her custom Givenchy dress a bit of glitz and glam. According to U.K.-based fine jewelry retailer Steven Stone, though, the royal family heirloom wasn’t her first choice for her big-day accessory. Instead, the Duchess of Sussex allegedly had her eye on an emerald-studded headpiece, the same one that Princess Eugenie would wear five months later. Queen Elizabeth II, however, rejected Meghan’s request.

Fine jewelry expert Maxwell Stone explained that when Meghan looked through the former monarch’s collection of tiaras at Buckingham Palace for her special wedding accessory, she originally picked a crown covered in emeralds and diamonds. Elizabeth quickly shut down her chosen design, providing the reasoning that it was tied to controversy. “Thought to have come from Russia, the headpiece is said to have found its way into the collection through undefined channels,” Stone said.

Stone explained that Meghan’s initial selection, which was unknown at the time, has actually been identified as the Greville Emerald Kokoshnik tiara—the very same crown that Princess Eugenie wore on her wedding day. The sparkling accessory features rose-cut pavé diamonds and six emeralds—with a 93.7-carat cabochon-cut emerald in the middle—set in platinum. It was reportedly the most expensive tiara in the late queen’s collection, with a price tag of nearly $13 million. The headpiece was commissioned by Boucheron in 1919 for Dame Margaret Helen Greville, a British society hostess and philanthropist who was friends with the Queen Mother. Margaret gave the piece to her friend, who passed it down to her daughter, Queen Elizabeth.

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In his forthcoming memoir, Spare, Prince Harry discussed the selection process—and eventual refusal—in more detail. Harry wrote that Elizabeth and her royal dresser, Angela Kelly, provided Meghan with a collection of five options, one of which was the emerald-covered diadem. The Duke of Sussex made it clear that one of the pieces “stood out form the others” and “was made for Meg.”

In another book about the royal family, Battle of Brothers: William & Harry by royal historical Robert Lacy, the royal dresser reportedly said Meghan preferred the emerald-studded crown, but it wouldn’t be able to leave the palace without “an ordinance and police escort.” Once the couple asked why the crown was off limits for Meghan’s big day, the author summarized the royal dresser’s response: “It would suit neither the palace nor Meghan herself that spring if newspapers started speculating about which Tsarist princess had worn the tiara and how she had been assassinated.” Harry was allegedly furious with that response.

Instead, on her special day, Meghan ended up donning Queen Mary’s Diamond Bandeau Tiara, a diadem composed of 10 brilliant diamonds. According to Stone, Mary received the base of the sparkly design, a brooch, as a wedding gift from County of Lincoln in 1893. Then, in 1932, the tiara was made to accommodate the brooch. Stone also estimates that the piece is worth at least $2.5 million, nearly $10 million less than her original choice.