The eternal Hercules in this film has gone way beyond his usual time and place in ancient Greece and is now helping Poland free itself of Mongol invaders in the 12th century. Poland is having its dynastic problems, with king in exile and a princess with a closer claim on the throne. She was hidden as an infant in a peasant village and not told of her lineage to protect her from the Mongols. Genghis Khan is having his problems with a pair of sons who both want to succeed dad and one of them is not too squeamish on what he has to do to take the throne.