Kate Middleton Stuns in Princess Diana's favorito Tiara 

Kate Middleton Stuns in Princess Diana's Favorite Tiara

Antoinette Bueno      8:05 AM PST, December 09, 2015

her late mother-in-law, Princess Diana, when the 33-year-old Duchess of Cambridge donned one of her favorite tiaras at a royal engagement.

Kate wore the show-stopping Cambridge Lover\'s Knot tiara at the annual Diplomatic Reception at Buckingham Palace on Tuesday night, which Diana had been photographed wearing on multiple occasions.

WATCH: Princess Charlotte Is Adorable in New Pics Taken by Kate Middleton

Previously, Kate\'s been known to sport the Lotus Flower tiara, a favorite of Queen Elizabeth\'s. The stylish royal wore that particular tiara in October at her first state dinner (in honor of the president of China), and again at the 2013 Buckingham Palace reception for diplomats -- the same event she attended on Tuesday night.

Curiously, Kate wore the exact same dress -- a baby blue lace Alexander McQueen gown -- and the exact same pair of diamond earrings at the 2013 event, highlighting her recent change in tiaras even more.

WATCH: Kate Middleton Can\'t Stop Smiling with William and Harry

Watch the video below to revisit Kate\'s bold red Jenny Packham gown and stunning tiara look in October.

Kate Middleton Celebrates 100th Anniversary of World War I in Style

Keith Urban Mourns His Father at Memorial Service

Khloe Kardashian Bares Her Naked Butt in Glitter-Covered \'Revenge Body\' Pics

Watch Kylie Jenner Lose Her Mind Over Tyga When He Crashes the Kardashian Family Vacation

\'The Bachelor\' & \'The Bachelorette\' Romance Check! Which Couples Are Still Together?

Gene Simmons\' Daughter Sophie Poses Nude After Being Body-Shamed As a Teenager