When Kate Middleton arrived at Westminster Abbey on her wedding day, April 29, 2011, all eyes were first drawn to her long-sleeved lace wedding dress by Alexander McQueen. But attention soon shifted to the stunning tiara on her head—the Cartier Halo, set with 739 brilliant-cut diamonds and 149 baguette diamonds.

Before the wedding, there had been much speculation about whether Kate would borrow a piece from Queen Elizabeth II’s vast jewelry collection. Some reports even suggested she might skip a tiara altogether and opt for a flower crown, as her mother, Carole, had done when she married Michael Middleton. In the end, Kate chose tradition, selecting a tiara rich in royal history.

The Cartier Halo tiara was originally a gift from the Duke of York (later King George VI) to his wife, the Duchess of York (later the Queen Mother), in 1936. She was first photographed wearing it at a charity ball in London that November—just weeks before King Edward VIII’s abdication made her husband king.

Queen Elizabeth later gave the tiara to her daughter, Princess Elizabeth, for her 18th birthday, though the future queen was never seen wearing it publicly. Instead, it was Princess Margaret and Princess Anne who were photographed in the piece before Kate wore it on her wedding day.

While the Halo tiara won’t be part of the upcoming V&A exhibition on Cartier, another royal-linked piece will: the Cartier Scroll tiara. Made for the Countess of Essex in 1902, it features 1,040 diamonds and was later worn by Clementine Churchill to Queen Elizabeth II’s coronation in 1953.

Today, the Scroll tiara remains in Cartier’s archives, though it made a rare appearance in 2016 when Rihanna wore it for a W magazine cover, styled by former British Vogue editor Edward Enninful.