After the evil King Sligon exiles his family from Scandia, Prince Valiant (Robert Wagner) vows to become a member of King Arthur's Knights of the Round Table in order to return his father to the throne. As he travels to Camelot, Valiant discovers the Black Knight, a villain conspiring with Sligon to destroy King Arthur. Under the eye of Sir Gawain (Sterling Hayden), Valiant trains to become a knight, falls for a princess (Janet Leigh) and unmasks the Black Knight.