The Duchess of Cambridge had a real-life princess moment when she and Prince William joined The Queen, Prince Charles and the Duchess of Cornwall at the annual Diplomatic Corps reception at Buckingham Palace on the evening of Wednesday, December 11, 2019.

While the 37-year-old’s sophisticated floor-length evening gown from the same design house behind her wedding dress—Alexander McQueen—was striking, it was the royal jewels that really stole the spotlight.

Dazzling the 1,000 guests in attendance and the royal family alike, the duchess looked like a fairytale princess with her favourite tiara, the Lover’s Knot, perched regally atop her perfectly coiffed up-do.

Indeed, with access to the treasure trove of incredible pieces within the royal family’s jewellery vault, even the duchess appears—like so many of us—to play favourites, selecting this one very special piece time and again for royal occasions.

This particular tiara was made by British jewellers Garrard, for Queen Mary in 1913 and features 19 diamond arches and 38 pearls. Queen Mary reportedly gave the piece to the now-Queen Elizabeth II, who then gave it to Princess Diana as a wedding gift.

Following Princess Diana’s tragic and untimely death, the tiara returned to The Queen, who has loaned it to her granddaughter-in-law, Middleton, to wear on numerous occasions over the years including a number of diplomatic receptions.

In fact, Middleton wore the Lover’s Knot tiara to the 2018 Diplomatic Corps reception, pairing it with a Jenny Packham gown. The duchess also donned her favourite tiara to attend the 2015, 2016 and 2017 editions of the annual white tie event.

Along with her favorite tiara, Middleton wore the breathtaking Nizam of Hyderabad diamond necklace, statement drop diamond earrings, her Royal Victorian Order blue and gold sash (which Hello! reports she was awarded this year) and her Royal Family Order brooch.

The event is a highlight on the royal calendar every year and is always a glittering affair in large part thanks to the white tie dress code and the festive spirit of the occasion; a spirit Kate Middleton certainly brought with her beaming smile and bewitching jewels.