The Queen and Duchess of Cambridge welcome diplomats at Buckingham Palace

Telegraph Reporters
The Duchess of Cambridge talks to guests at an evening reception for members of the Diplomatic Corps at Buckingham Palace in London - PA

The Duchess of Cambridge has once again opted for a tiara favoured by Diana, Princess of Wales, for a glittering reception at Buckingham Palace.

The Lover's Knot tiara was Kate's star accessory at the annual white-tie Diplomatic Corps reception, where she and other senior royals dressed in their finery.

At the evening reception on Wednesday, Kate matched the diamond and pearl tiara with a navy velvet gown by Alexander McQueen, a combination she opted for earlier this year.

The duchess wore the sparkling headpiece with a white ruffled Alexander McQueen gown for a state banquet hosted during Donald's Trump three-day state visit in June.

The diamond and pearl tiara once belonged to her mother-in-law Diana, who famously teamed the heirloom with a white sequined dress and high-collared jacket by Catherine Walker.

Queen Elizabeth II talks to guests at an evening reception for members of the Diplomatic Corps at Buckingham Palace in London Credit: Victoria Jones /PA

The piece was originally made for Queen Mary, the Queen's grandmother, in 1914 by the House of Garrand, using pearls and diamonds belonging to her family.

Its design was taken from a tiara owned by Mary's grandmother Princess Augusta of Hesse, known as the Cambridge Lover's Knot Tiara.

Pictured smiling and talking to guests at the Diplomatic Reception, Kate also wore her sash and star of the Dame Grand Cross of the Royal Victorian Order.

The duchess, who joined the Duke of Cambridge at the event, paired the tiara with shimmering drop earrings and a matching statement necklace.

The Duchess of Cornwall opted for a cream embroidered gown by Bruce Oldfield, a diamond Boucheron tiara and pearl choker and pearl earrings on Wednesday.

Queen Elizabeth II at an evening reception for members of the Diplomatic Corps at Buckingham Palace in London Credit: Victoria Jones /PA

A similarly coloured gown was worn by the Queen, who dressed in a lace trimmed Angela Kelly state gown and the Vladimir tiara with emerald and diamond drops.

She also wore white gloves and carried a silver handbag.

The annual event is held every December for members of the Diplomatic Corps to enjoy an evening at the palace.