The 1956 film The Conqueror is often dismissed by movie critics as an attempt by John Wayne to expand his image and repertoire. If you aren’t familiar with the film, it stars the popular actor as the legendary Mongol leader Genghis Khan. Yes, “The Duke.” That John Wayne.

The film was produced by legendary playboy Howard Hughes, who was willing to spend a great deal of his fortune to make it a hit. He paid big bucks to get John Wayne to put his cowboy boots aside and to put on a silly-looking Fu Manchu mustache.

Once Hughes got his leading man, he moved production to the mountains and deserts of southern Utah. Many of the scenes were shot near the town of St. George, Utah, about one hundred thirty-seven miles downwind from the Nevada Test Site (NTS), which is where the U.S. military tested its nuclear weapons in the 1950s and 1960s.

The testing didn’t stop while The Conqueror was being filmed.

Once location filming wrapped up in Utah, the ever-eccentric and obsessive Hughes then had several tons of Utah dirt delivered to the Hollywood studio where the final scenes were filmed. Although The Conqueror was panned by most critics, it did well at the box office thanks to the popularity of The Duke. 

But then, people started getting sick.

Director Dick Powell died of cancer in early 1963, and star Pedro Armendáriz took his own life in June of 1963 after fighting kidney cancer for three years. The list of doomed stars and production members continues on: Leading lady Susan Howard died of brain cancer in 1975, star Agnes Moorhead succumbed to uterine cancer in 1974, star John Hoyt died of lung cancer in 1991, and leading man Wayne died of stomach cancer in 1979. Of the two hundred twenty cast and crew members who worked on the movie at the St. George location, ninety-one developed some form of cancer and forty-six people died of the disease.

Those are certainly shocking numbers. Skeptics, however, point out that a majority of the cast and crew smoked cigarettes.

Even so, the number of cancer cases associated with The Conqueror is higher than for any other known movie.

Hughes reportedly also felt remorse for his role in the situation. He bought all of the prints of the film, which effectively took it out of circulation until after his death.  When the film began appearing on television in the 1980s, viewers were amused by Wayne’s phony mustache and the fact that he didn’t try to change his accent for the role. That amusement, though, turned to bemusement when details about the film set’s detrimental impact on the health of the cast and crew were revealed.

Whether or not nuclear weapons testing led to the unnatural deaths of the cast and crew of The Conqueror will never be known for sure, but it is interesting that the major nuclear powers of the world agreed to ban aboveground nuclear weapons testing in 1963.