During production, Steve Reeves suffered a major injury. A chariot he was driving struck a tree and he dislocated his shoulder. The injury never fully healed, putting an end to the more intense bodybuilding routines he had done for most of his life.
Director Mario Bonnard reportedly fell ill on the first day of shooting. The film was directed mostly by Sergio Leone, who was one of the screenwriters.
Many of the same cast and crew members would be hired for Sergio Leone's first credited directorial effort, "The Colossus of Rhodes" (1961).
It was reportedly during the production of this film that Sergio Leone, Sergio Corbucci and Duccio Tessari were introduced to the deserts of Spain. This would inspire their use of these locations for the genre that would be known as "spaghetti westerns."
To create the spectacular eruption of Mount Vesuvius, the production hired Italian master pyrotechnician/powderman Eros Bacciucchi. This would be his first job as a member of a motion picture special effects team and lead to a more than 25 year career in the industry, including a number of collaborations with director Sergio Leone.