Two new portrait photographs of a beaming Duchess of Cambridge will go on public display from Sunday.
Kate is shown looking casual and relaxed in the pictures, taken in the Norfolk countryside earlier this year, in a marked departure from more formal official images of the Royal Family.
In a black-and-white close-up shot, the Duchess is wearing a black fedora hat from Beyond Retro and a charcoal brown double-breasted suede coat and white shirt, both from Burberry.
In another, a colour photo shot in soft January sunlight, Kate is leaning on a rustic gate, wearing a black and red striped long-sleeved top from Petit Bateau and black Burberry trousers.
The photos, taken by British photographer Josh Olins, will hang in the National Portrait Gallery, where Kate has been a patron since 2012.
A Kensington Palace spokesman said: "The Duchess was delighted to play a part in celebrating the centenary of an institution that has given a platform to some of the most renowned photographers in this country's history.
"She is incredibly grateful to the team at Vogue and at the National Portrait Gallery for asking her to take part.
"She would like to thank Josh Olins for being such a pleasure to work with. The Duchess had never taken part in a photography shoot like this before. She hopes that people appreciate the portraits with the sense of relaxed fun with which they were taken."
Olins, who has worked on advertising campaigns for a host of high street and designer fashion brands, said Kate was "a joy to work with, a natural".
The Royal Family are no strangers to being photographed by the world's best fashion photographers - the Queen was recently pictured in separate images with her beloved corgis and the royal children by Annie Leibovitz for her 90th birthday.
And Kate has been known to go behind the lens, including one photo showing a proud Prince George kissing his then newborn sister Princess Charlotte.
The latest photos of the Duchess were styled by British Vogue fashion director Lucinda Chambers and a colour image of the Duchess in the brown Burberry coat and fedora will adorn the cover of the magazine's June centenary issue.
A further five pictures will appear alongside an article inside the edition.
Vogue 100: A Century Of Style runs at the National Portrait Gallery in central London until May 22 this year.