Nick Cravat, who plays Piccolo, was an acrobat who was teamed with Burt Lancaster before Lancaster became a star. He appears in many of Lancaster's movies. In this one, and in Il corsaro dell'isola verde (1952), he plays a mute. The reason was that his thick Brooklyn accent, which he could not lose, would have been wildly out of place in such period pieces.
After Warners' publicity department claimed that Burt Lancaster did all his own stunts, it raised the ire of veteran stuntman Don Turner, who stood in for the actor in at least three fight scenes although he sought no credit for the acrobatic scenes.
Veteran stuntman Duke Green was seriously injured doing a stunt in this film. He was supposed to catch his foot in a snare on a forest pathway and be whipped upright off his feet. The rigging from the platform above him broke, and he plunged to the ground, breaking his neck. He eventually recovered to a degree and did some minor stuntwork in the years following, but the injury effectively ended his 25-year career as a stuntman.
Although numerous sources have claimed that the project was originally intended for Errol Flynn, by 1950 Flynn's physical condition had deteriorated to a point that precluded his playing the role.
Dardo tells his son Rudi to aim low when firing his arrow. In archery this is correct. Unlike aiming a rifle, where the barrel is leveled at the target, an archer aims the tip of the arrow somewhere below the target up until a distance of 30 or 40 yards, depending on the power of the bow.