The evil King Zagro (Livio Lorenzon) asks the king of a neighboring country (King Alteo) for permission to wed his daughter, the beautiful Princess Sira (Wandisa Guida), a political union that will join their two countries together. The mighty warrior Ursus, who fought for years in the army of King Alteo, has retired from the military to run a farm in the countryside with his little brother Dario. Ursus had once asked Alteo for the hand of the princess himself, but the king turned him down because Ursus was not of noble birth.