The Duchess of Cambridge has been one busy royal these past few days, first hosting a Christmas party for families of serving military personnel followed by a trip to Cyprus to bring gifts to servicemen and women. But in between these festive occasions, Kate amped up the glamour in a stunning new gown and her favourite tiara for the Queen’s annual Diplomatic Reception at Buckingham Palace on Tuesday evening (Dec. 4).

Kate’s Cambridge Lover’s Knot tiara, the crowning jewel of her look, is her go-to topper and holds special significance as it was a former favourite of Princess Diana. The gorgeous piece, perfectly complemented by her pearl earrings, features an eye-catching pearl and diamond pattern that was originally created for the Queen Mother. She also wore this tiara at the state dinner with Queen Máxima and King Willem-Alexander.

MORE: All the photos from Prince William and Kate's visit to Cyprus

The duchess opted for an ethereal new Jenny Packham gown in the faintest blue, boasting a soft tulle overlay, a nipped waist, gathered cap sleeves and silver adornments. Among the mother of three’s heavy-hitting accessories was her Royal Family Order – a yellow ribbon pinned her her gown with a glass portrait of Her Majesty and diamonds. A gift from the Queen to female members of the Royal Family, the 36-year-old first wore the pin at last year’s Diplomatic Reception, and again for a state dinner with the Dutch royals in October.

Joining the mother of three were other senior members of the family, like the Queen and the Duchess of Cornwall, who also dazzled in their own high-end attire! Camilla went with a stunning white satin gown, topping off her look with a tiara, while the monarch dazzled in a champagne-and-white tiered gown and the Ireland Tiara, one of her favourites.

Duchess Kate has been stunning in dazzling new looks of late. While hosting a Christmas party at Kensington Palace the morning of the reception, she was the picture of festive in a tartan Emilia Wickstead skirt paired with a black cashmere cardigan by Brora and black slouchy boots. After pulling out all the stops for the reception – which had a dress code of “white tie and decorations” – Kate stepped out with William in Cyprus for a rare trouser moment, completing the look with a chic military-green blazer by Canadian label Smythe.