Prince William has been joined by fiancee Kate Middleton at a Christmas charity variety show.
It was the couple's first joint engagement since plans for their wedding were announced last month.
Miss Middleton walked by the prince's side as the couple arrived for the concert, staged to raise funds for the Teenage Cancer Trust.
William joked with onlookers, telling one group of teenagers dressed as elves: "Cool hats".
Miss Middleton waved and smiled at well-wishers but said nothing.
The prince was guest of honour at the fund-raising gala in Thursford in Norfolk, which showcased a cast of professional singers, dancers and musicians.
The Thursford Christmas Spectacular, held at the Thursford Collection, was a private event but during the interval the prince was to meet a group of young cancer patients from Norfolk and Hertfordshire as well as staff from the charity.
Proceeds from the evening will go towards the construction of the first specialist cancer unit for young people at Addenbrooke's Hospital in Cambridge, which will cost £2.5 million.
The unit will be designed to reflect a young person's life outside hospital as closely as possible, unlike other ordinary hospital wards where young cancer patients may be placed on children's wards with babies and young children on adult wards alongside elderly patients.
William was invited to the event by Emilie Van Cutsem, chairman of the Teenage Cancer Trust's East Anglia volunteer committee, and also a close friend of the prince and his family.