Whenever Duchess Catherine steps out in a ballgown and tiara, she never fails to amaze us with her timeless elegance.
And after an invitation to a white tie evening reception at Buckingham Palace was leaked on social media, it's expected that the Duchess of Cambridge will dazzle in another formal ensemble for the proceedings, and it will be her last for 2019.
The Queen is set to host the annual Diplomatic Corps Reception at Buckingham Palace on 11th December, one of the final royal events before she and the family head to Sandringham for Christmas.
Government officials, including ambassadors and high commissioners to the UK, usually attend along with senior members of the royal family, and seeing as they have attended for the last four years, we can safely assume that Prince William and Duchess Catherine will be there.
The invitation states that the dress code is White Tie or National Dress or Full Ceremonial Evening Dress for Serving Officers. So as the fanciest of the dress codes, we can expect to see Duchess Catherine in a sparkly headpiece.
For last year's Diplomatic Reception, Duchess Catherine looked breathtaking in a silvery blue gown by Jenny Packham, one of her favourite designers.
The look was topped off with the Cambridge Lover's Knot tiara- an heirloom headpiece that the Queen inherited from her grandmother Queen Mary, before giving it to Princess Diana as a wedding present in 1981.
The tiara is thought to be Duchess Catherine's favourite as she has worn it seven times since becoming a member of the royal family, which many fans suspect is a sweet tribute to her late mother-in-law.
The last time we saw Duchess Catherine in her evening finery was when the royals hosted a state banquet for US President Donald Trump and First Lady Melania Trump.
The Duchess of Cambridge stole the show in a long white Alexander McQueen gown paired with her trusty Cambridge Lover's Knot tiara and also wore her blue, red and white sash of the Victorian order - a mark of honour gifted to her by the Queen for her and Prince William's eighth wedding anniversary.
Watch the royals arrive at the state banquet in the player below. Post continues after video...
Duchess Catherine has only been seen wearing a tiara on 10 occasions, including on her wedding day in 2011 - and it's for a simple reason.
"The first time a tiara is worn is by the bride on her wedding day. It signals the crowning of love and the loss of innocence to marriage," author Geoffrey Mun explained in his book Tiaras - A History of Splendour.
"The family tiara is worn by the bride and from that moment onwards it was the groom's jewellery she was expected to wear. It was a subliminal message that she had moved from her family to another. Nowadays few adhere to this protocol, even if they are aware of it."