Prince of Time (The After Cilmeri Series)

Two teenagers are catapulted back in time to alter history and save the medieval kingdom of Wales ...
 
David and his man-at-arms, Ieuan, find themselves alone and on the run from a company of English soldiers who've sworn vengeance for the recent death of their king. Meanwhile, Llywelyn lays on his deathbed, wounded by a traitor's arrow.  And once again, it is David and Anna, and all that they represent, that holds the key to the survival of Wales.