Genghis Khan in The Conqueror (1956)
Portrayed by: John Wayne
The Conqueror is often ranked as one of the worst films of all time, and not just because of the tagline: “I am Temujin Barbarian… I fight! I love! I conquer… like a Barbarian!” It's also a wreck because John Wayne, Hollywood’s prototypical cowboys, portrays Mongolian emperor Genghis Khan by wearing makeup.
Another fun fact: A number of members of the cast and crew later suffered from cancer due to the locations used for filming. In other words, none of this should've happened.