I saw this question on Twitter from http://storycasting.com/ . Good question. In 2000 while I was writing the 1st draft of The Unhewn Stone, I decided that Heath Ledger, the Australian actor who played in A Knight's Tale would make an ideal Stefan (a modern Swiss youth who travels back to 1307AD). But it took so long to finish the novel that the actor had outgrown the part, and then, sadly, he died too young. I haven't been able to think of a suitable replacement. He needs to be able to portray an 18yr old blue-eyed blond, two inches taller than his medieval counterparts. Petulant and proud to begin with.
The main girl is a shape shifting sibyl. She is a dark-eyed dark-haired beauty, the girl of his dreams who becomes a courtier, a Snow White figure, an old crone and a bat.
I think the actors will have to be newcomers. Unknowns who become famous because of their superb acting in the roles of my characters.
Who would play your leading characters?