Basra merchant Harun Al-Rashid avenges his father's murder in this adventure set in ancient Bagdad and inspired from the Arabic fairy tales of One Thousand and One Nights.

After completing his voyages Sindbad the Sailor and his hearty crew have come home to find a palace coup d'etat has occurred and his home city is being run by a brutal dictator played by Pedro Armendariz. He's got designs on the beautiful young princess, Heidi Bruhl both lustful and political.

In the London of 1537, two boys resembling each other exactly meet accidentally and exchange "roles" for a short while. After many adventures, the prince regains his rightful identity and graciously makes his "twin" a ward of the court.