The duchess wore the glittering diamond and pearl tiara at the Buckingham Palace state dinner on Tuesday night with an Alexander McQueen gown.
And while the mother of three was praised for her nod to the late princess, choosing to wear Diana's memorable tiara to the banquet, fans on social media were confused by the duchess' choice of dress.
Max Mumby/Indigo via Getty Images A closer look at William's outfit and Duchess Kate's jewels.
The duchess has worn the tiara on several other occasions, including diplomatic receptions at Buckingham Palace in 2015 and 2016, and a state banquet in honor of King Felipe and Queen Letizia of Spain 2017, according to Harper's Bazaar. She looks like a queen now because she looks utterly comfortable wearing the trappings.More news: Pressure on Saudis over missing Khashoggi
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Kate finished the look with the diamond and pearl Cambridge Lover's Knot tiara owned by Princess Diana, which she also wore to the Chinese state banquet in 2015 and the Spanish state banquet a year ago. Online, the tiara is more than 100 years old and belongs to Queen Elizabeth, although it was originally commissioned in 1914 for the queen's grandmother, Queen Mary.
The Duchess of Cornwall, 71, was the picture of elegance in an embroidered ivory coat dress and the Queen Mother's Greville tiara, which was loaned to her by the monarch for the evening.
Diana also wore the tiara in 1985 on an official visit to Washington with Prince Charles.
Queen Elizabeth II hosted the dinner for King Willem-Alexander and Queen Máxima of the Netherlands. It was one of her most important marital presents, coming from her groom himself, and she wore it on their wedding day at St. George's Chapel, Windsor.