Viking Prince Einar (Kirk Douglas) doesn’t know it, but his most fearsome enemy, the slave Eric (Tony Curtis), is actually his half brother. Their feud only intensifies when Einar kidnaps Princess Morgana (Janet Leigh), the intended bride of the brutal King Aella (Frank Thring). Einar intends to make the beautiful girl his own. Unfortunately for him, Morgana has eyes only for Eric — leading to much bloodshed and the capture of their father, King Ragnar (Ernest Borgnine).