One of the winning entries in Young Artists' Britain

"These are very capable and competent works. It's a skill which isn't evident in his earlier works, when one was very much aware of being in the presence of an artist who was an amateur," he said.

Prince Charles' development as an artist can be attributed to the influence of the artists who have accompanied him on royal tours for the past 15 years.

They are allowed to sketch and paint whatever they want, and the pictures being exhibited show the intricacies of life on a royal tour, from attending official ceremonies to the nitty-gritty of life behind the scenes.

But according to one of the artists, Susannah Fiennes, conditions are often difficult.

"You have to have your wits about you. You have to use your initiative and find subjects that interest you, often under intense pressure between one official function and another.

"There's the anxiety of not being left behind - when the prince moves, you have to follow him," she said.