As you know, tiaras are a big deal in the royal family, especially on their wedding day. In fact, Princess Beatrice has probably already decided which tiara she's wear on her big day next year.
Most tiaras are given to the bride as a gift for the big day, or borrowed from the Queen's collection. For example, Prince Harry helped Meghan pick her art deco tiara from the vault for their wedding, whilst Princess Eugenie's Greville emerald and diamond tiara, also on loan, is considered the most expensive royal tiara.
However, both Princess Diana and the Duchess of York received a tiara as a gift for their own big days, but Fergie was the only one to get to keep hers.
That's because the York tiara as it became known, was specially commissioned by the Queen as a wedding day present, as opposed to coming from the royal family's private estate.
Though we know that Princess Diana wore her own family's Spencer tiara (which is still in their possession) on her wedding day in 1981, the Queen did offer her the gorgeous diamond and pearl Lover's Knot tiara to wear, which Diana respectfully declined, but then wore on several occasions during her years as a royal.
However as the tiara was part of the royal collection, by law she had to give it back after her divorce in 1996, as she was no longer part of the royal family.
It is now believed to be one of the Duchess of Cambridge's favourites, and she was photographed several times wearing it at official events.
