The Duchess of Cambridge has toured an art exhibition of Victorian photography - a subject she studied during her degree.
Kate visited the collection of pioneering photographs at the National Portrait Gallery in a snowy London on Wednesday evening.
The history of art graduate has written several captions for the images at the exhibition Victorian Giants: The Birth of Art Photography.
In a foreword to the exhibition, Kate wrote: "This period in the history of photography has long interested me.
"As a student at the University of St Andrews, I chose it as the subject of my undergraduate thesis and photographs of children in particular, which feature predominantly within the exhibition, are of real interest to me."
But unfortunately her dissertation is nowhere to be found - lost in the family paperwork.
Exhibition curator Dr Phillip Prodger said: "She was very self deprecating about that, and she did explain to me that somewhere in her family archives she has stashed away her undergraduate thesis, and there was a moment when she asked her family if she couldn't retrieve it, but no one could find the document."
Pregnant Kate, patron of the gallery since 2012, wore a mid length black dress with a flower print on by Orla Kiely.
After touring the exhibition, she enjoyed a reception, meeting guests including staff who have worked on the collection.
The display will show together for the first time portraits by influential artists Oscar Rejlander, Lewis Carroll, Julia Margaret Cameron and Lady Clementina Hawarden.
An enthusiastic amateur photographer herself, Kate has released photographs of her own children to mark the milestones in their lives, including George's first day at nursery and Charlotte's first birthday.
It was the second royal engagement of the day for Kate, who earlier attended a forum with her husband the Duke of Cambridge, Prince Harry, and Meghan Markle to celebrate the work of the Royal Foundation.