The Duchess of Gloucester wowed at a state banquet held at London's Guildhall, held in honour of France's President Emmanuel Macron and First Lady Brigitte Macron on Wednesday night.
The white-tie event called for gowns and tiaras, and we think that the Duchess may own one of the most versatile tiaras in the British royal family's collection.
Danish-born Birgitte, who married the late Queen's cousin, Prince Richard, in 1972, wore Queen Mary's Honeysuckle tiara for the banquet.
According to the Court Jeweller, the sparkling diamond headpiece was made by E. Wolff and Co on a commission for Garrard for Queen Mary in 1914.
Mary passed the jewels down to her daughter-in-law, Princess Alice, Duchess of Gloucester, who then gave the tiara to her own daughter-in-law, Birgitte.
The headpiece has a central element shaped like a honeysuckle, but this motif can be disassembled and swapped with another gemstone.
The Duchess of Gloucester wore the tiara with a striking pink gemstone, known as kunzite, on Wednesday night.
But over the years, she has sported the jewels with its honeysuckle element, as well as an emerald, meaning the tiara can be adapted according to her outfit.
The Duchess of Gloucester's tiaras
The Guildhall state banquet wasn't Birgitte's only tiara moment of this week. The Duchess joined the rest of the senior royals and the King and Queen as they hosted the Macrons for the state banquet at Windsor Castle on Tuesday night.
The Duchess wore a cream three-quarter-length sleeve gown with Queen Mary of Teck's Turquoise set – including the tiara, necklace, earrings and brooch.
While Birgitte did not wear a tiara on her wedding day, she has several others in her collection – including the Cartier India and the Iveagh.