The Black Knight(1954)

John, a blacksmith and swordsmith, is tutored at Camelot. As a commoner, he can't hope to win the hand of Lady Linet, daughter of the Earl of Yeoniland, 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.