Princess Kate wears Princess Diana's favourite and extremely heavy tiara

The Duchess of Cambridge wore the late Princess Diana's favourite tiara. Photo / Getty Images

Kate Middleton is already Britain's sweetheart so it shouldn't come as much of a surprise to see her channelling the likes of the late 'People's Princess' and her mother-in-law Princess Diana.

On a rare outing to Buckingham Palace, the Duke and Duchess of Cambridge headed to the London palace for the annual Diplomatic Reception.

Draped in jewels, Kate wore the Cambridge Lover's Knot Tiara which was once a favourite of Princess Diana's.

The tiara was made back in 1914 from Queen Elizabeth II's own design and with pearls and diamonds already owned by the Royal Family.

Prince Harry was missing in action however their father Prince Charles, his wife Camilla and Queen Elizabeth II and her husband Prince Phillip were all in attendance.

The iconic and unique photo of the 'magnificent six'. Photo / Getty Images

The image of the 'magnificent six' is an extremely rare one and was the first time a photographer was allowed to take photos at the reception which is normally extremely secretive.

The Duchess wore a dress from one of her favourite designers Jenny Packham to the lavish event.

Diamond chandelier earrings accented her flowing red gown with its tailored waist and delicate bodice and was the second time the Duchess stunned in red having worn it for the state visit of Chinese President Xi Jinping.

Kate wore the Cambrige tiara for the first time last year to the same Diplomatic reception which was the first time the tiara had been worn after Diana's death in 1997.

Queen Elizabeth II gifted the shimmering tiara to Diana in 1981 as a wedding present.

The young Princess of Wales wore the tiara regularly despite admitting it was so heavy it often gave her headaches.

The 34-year old Duchess already carries a part of Princess Diana with her everywhere she goes after William proposed with his mother's engagement ring.

In an interview following their 2010 engagement, William said "Obviously she's not around to share the fun and excitement of all this, so, this is my way of keeping her sort of close to it all."

The ring, made with a large sapphire and set with a number of diamonds is valued at more than £1 million.