John (Alan Ladd), a blacksmith and swordsmith, is tutored at Camelot. As a commoner, he can't hope to win the hand of Lady Linet (Patricia Medina), daughter of the Earl of Yeoniland (Harry Andrews), so he creates a secret alternate identity as the Black Knight. In this new role, he is now able to help King Arthur when Saracens and Cornish men—disguised as Vikings -- plot to take over the country.
Gawain was a squire in King Arthur's court when the Green Knight burst in and offered to play a game with a brave knight. Gawain journeys across the land, learning about life, saving damsels, and solving the Green Knight's riddle.