Henry Hathaway's Arthurian adventure is based on the popular newspaper cartoon strip by Hal Foster. Robert Wagner plays the eponymous prince, a Viking invited to join King Arthur's court. But the evil Sir Brack plans to oust the king and then invade Valiant's Scandanavian home and only Valiant can stop him. Janet Leigh and Debra Paget are the respective love interests to both parties and, with much of the film being shot in Britain rather than on a Hollywood back-lot, viewers will enjoy identifying castles and locations that form a backdrop to the rousing action.