The Duchess of Cambridge has honoured both the Queen and her late mother-in-law, Princess Diana, in a series of stunning birthday portraits.

Kate, who celebrated her 40th birthday on January 9, released the three portraits to mark the milestone occasion making sure to pay tribute to both Princess Diana and Queen Elizabeth with some subtle wardrobe choices.

In one photo Kate is seen wearing a one-shoulder red satin gown and a pair of diamond earrings that belonged to the Queen.

In a second black and white photo, the Duchess is wearing diamond and pearl drop earrings that belonged to Princess Diana.

The photos were taken by Paolo Roversi at London’s Kew Gardens and will become part of a permanent collection at the National Portrait Gallery, in London, as part of the institution’s “Coming Home” project, which features portraits of well-known people in various locations that have special meaning to them.

While discussing the photoshoot, Roversi reflected on his time with the Duchess telling Italian newspaper Corriere della Sera, “She is a nice, welcoming woman who puts you at ease, respectful of everyone’s work”.

Kate is reported to have a low-key birthday celebration at home with her husband Prince William, and their three children George, Charlotte, and Louis, according to The Sun.

The Queen marked Kate’s 40th birthday by sharing her well wishes in a touching Instagram post.

Shared on the official Royal Family Instgram page, the post included a series of photos of the Her Majesty alongside the Duchess of Cambridge with a caption reading, “Wishing The Duchess of Cambridge a very happy 40th birthday today!”.