Kate Middleton Just Wore a $135 Million Heirloom Tiara That Was One of Princess Diana's Favorite Pieces

Kate Middleton is paying homage to Queen Elizabeth and Princess Diana with her chosen look for the state dinner held tonight, September 17, 2025, at Windsor Castle. For the occasion, the princess donned a cream-hued gown crafted by Phillipa Lepley, a British designer, which she paired with a hand-embroidered gold Chantilly lace coat. She accessorized her look with drop earrings that once belonged to Queen Elizabeth and Queen Mary's Lover's Knot Tiara. The latter is estimated to be worth $135 million, according to Maxwell Stone, an expert jeweler.

Kate last wore the iconic diadem for another state dinner: the visit of French President Emmanuel Macron and his wife, Brigitte Macron, on July 8, 2025. For that occasion, the princess paired the jeweled piece with a long-sleeve, cape-style gown from Sarah Burton, the designer of her 2011 wedding dress. For that affair, she also donned earrings that were originally part of Queen Elizabeth's collection. The high-profile event marked the first time Kate had worn a tiara since 2023.

What Is the Significance of the Lover's Knot Tiara?

While the tiara wasn't the one Kate selected for her own 2011 nuptials at Westminster Abbey, the piece holds particular significant to the royal family. The tiara was originally created by Garrard for Queen Mary in 1914, using pearls and diamonds that already owned by the family, according to Town & Country. When the monarch died in 1953, the piece was given her granddaughter, Queen Elizabeth. However, while the heirloom may have been significant to Queen Mary, it appears that Queen Elizabeth didn't share the same love for the jeweled accessory; she only wore it a handful of times over the course of her life. In 1981, she reportedly gifted the diadem to Princess Diana for her wedding to Prince Charles.

However, Diana decided not to wear the diadem for her royal nuptials, opting for the Spencer Tiara, which featured heart-shaped scrolls, instead. That piece, which dates back to 1767, had been passed through the Spencer family since the start of the 20th century. However, while the princess may not have donned the heirloom for her ceremony, she did select it for a number of other high-profile events, leading some to speculate that it was one of her favorites from the royal collection.

After Diana and Charles split in 1996, Diana returned the diadem to Queen Elizabeth. When Kate tied the knot with Prince William in 2011, she opted to wear the Cartier Halo Tiara, which was a gift to the Queen Mother from King George VI in 1936, rather than the beloved heirloom, which is now one of her most-worn tiaras. The Lover's Knot was first spotted as part of her ensemble for a high-profile occasion in 2015—when she selected it for a reception at Buckingham Palace.