The Roman Empire is under the harsh rule of Emperor Caracalla, and it's his extreme cruelty that pushes "Marcus" (Gordon Scott) toward becoming a gladiator. He had been protecting princess “Nisa” (Wandisa Guida) as she tried to escape when they were captured and sold into a difficult situation. Their new owner, “Valerio” (Roberto Risso), is an agreeable man who even develops feelings for his captive, but their hopes …