Le conquérant

The film is sometimes called "An RKO Radioactive Picture." It was filmed near an active nuclear test site in Utah, where 11 tests had reportedly been carried out in the year before the production arrived. The set was contaminated by nuclear fallout, but the Atomic Energy Commission assured Howard Hughes and the local population that the area was completely safe. Photographs exist of John Wayne holding a Geiger counter that reportedly made so much noise that he thought it was broken. After location shooting, Hughes had tons of contaminated soil transported back to Hollywood in order to match interior shooting done there. Over the next 30 years, 91 of the 220 cast and crew members developed cancer. Forty-six died, including John Wayne, Susan Hayward, Pedro Armendáriz (who shot himself soon after learning he had terminal cancer), Agnes Moorehead, John Hoyt, and director Dick Powell. Lee Van Cleef had throat cancer, but died of a heart attack. The count did not include several hundred local Native Americans who played extras, or relatives of the cast and crew who visited the set, including John Wayne's son Michael Wayne. A "People" article quoted the reaction of a scientist from the Pentagon's Defense Nuclear Agency to the news, "Please, God, don't let us have killed John Wayne." As of June 2011, the article is available in its archive online. It has however been suggested that many of the cast and crew died of cancer as a result of smoking. John Wayne had smoked 3-5 packs of cigarettes a day since the early 1930s, and many of the other actors and crew members were also heavy smokers.

When Temujin throws a spear at a man in a stream, the wire guiding it is visible. The spear's trajectory is also wobbly.

Featured in The World According to Smith & Jones: The Middle Ages (1987)