If Queen Mary of Denmark is not on your style radar, you are seriously missing out. Her wardrobe has been compared to Kate Middleton's many times over the years, but the Danish queen, who ascended the throne with her husband Frederik X in January, wore a dazzling tiara on Tuesday, October 8.

Even if you are not familiar with the name Lover's Knot Tiara, you have no doubt seen it in pictures. Remember Princess Diana's iconic “Elvis” dress, the high-collared, pearl-covered jacket? In this photo of her outing in Hong Kong, she is wearing a sparkling diamond piece with pearl drops.

Today, this tiara is most often worn by Princess Diana's daughter-in-law, the Princess of Wales, who first wore it out in 2015. In fact, Kate has worn the tiara a whopping 11 times over the years and has only deviated from the classic style a few times.

Ironically, the piece's official name is Queen Mary's Lover's Knot Tiara, and at Tuesday's dinner at Christianborg Palace, Mary Queen of Denmark wore the Danish equivalent of the royal Danish pearl and diamond headpiece.

According to The Court Jeweller, a royal jewelry blog, Queen Mary's tiara, known as the Pearl Poire Tiara, was made for Princess Louise of Prussia in 1825. It passed to the princess's granddaughter, Queen Lovisa of Denmark, and was transferred to the Royal Danish Property Trust after Queen Lovisa's death. Since then, only Danish queens have worn the historic tiara.

Mary has only worn the tiara once since King Frederik was crowned in January.

At this week's state dinner (held in honor of the visit of Icelandic President Hala Tomasdottir and her husband Björn Skrason), the Australian-born Mary layered additional diamonds to match the historic headpiece, including a stately She chose a riviere necklace and drop earrings.

Jewelry aside, Mary made the bold move of wearing her long-owned separates instead of a new evening gown.

Earlier in the day, Queen Mary had once again donned an outfit associated with the British monarchy, wearing the same jeweled purple coat dress she wore to Charles III's coronation in May 2023.

This time, she updated the outfit for daytime by adding a chic purple headband and wrapping a cozy gray pashmina around her neck.

As for the Lover's Knot tiara, royal fans may soon see it again when Princess Kate appears at a diplomatic reception at Buckingham Palace in December.