Kate Middleton has paid tribute to her late mother-in-law, Princess Diana, in a very special way.

The Duchess of Cambridge, 33, donned Diana's Lover’s Knot tiara — which was commissioned by Queen Mary in 1913 and made known by The People's Princess — to a Diplomatic Reception at Buckingham Palace on Tuesday, Dec. 8.

kate middleton lover’s knot tiara

Kate wearing the Lover's Knot tiara in December 2015.

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Princess Diana famously sported the stunning tiara to the State Opening of Parliament in 1981. This is the first time the crown jewel — which was a wedding gift to Prince Charles' bride from Queen Elizabeth at her 1981 wedding — has been worn since Diana's tragic death at age 36 in a 1997 car accident.

princess diana lover's knot tiara

Diana wearing the Lover's Knot tiara in November 1989.

This is only the fourth time Kate has donned a tiara; she previously wore the royal family's Cartier Halo tiara to her 2011 wedding, and the Lotus Flower tiara to both a 2013 Buckingham Palace reception for diplomats and to a 2015 royal state banquet.

Click through the gallery below to see more photos of Kate wearing the Lover’s Knot Tiara!