William Thatcher, a peasant, is sent to apprentice with a Knight named Hector as a young boy. Urged by his father to "change his Stars" he assumes Sir Hector's place in a tournament when Hector dies in the middle of it. He wins. With the other apprentices, he trains and assumes the title of Sir Ulrich von Lichtenstein. By law, only Knights may compete. Being of humble birth, William aquires fake documents to support his new identity. At his first tournament, he meets the lovely Jocelyn who is a Lady and has no idea that William isn't noble. He also creates an enemy in Count Ademar, until then the best Knight in the games, and a rival for Jocelyn's affections. William goes on to win many tournaments and Jocelyn's love. Ademar discovers William's humble beginnings and turns him in. William is promtly arrested. The Black Prince Edward, who William had paid a past kindness to, makes William an official Knight of the Realm, thereby making it legal for him to compete. He beats Ademar, and he and Jocelyn celebrate.