Sam Peckinpah wrote the original script and was set to direct, but Yul Brynner didn't like the script because it made Pancho Villa - a man who had given standing orders to shoot all prisoners - "look like a bad guy". Peckinpah was fired and his script was rewritten by Robert Towne to conform to Brynner's idea of what Villa was like.
According to Producer Norbert Saada's interview in documentary "Once Upon A Time Sergio Leone", Italian director Sergio Leone was offered to direct, but turned it down, because he did not like the cast of Yul Brynner in the title role.
The first of three movies which Robert Mitchum made in Europe. This was filmed in Spain , and he then headed to Italy for Edward Dmytryk's " Anzio" and followed that with a brief stint on Joe Losey 's " Secret Ceremony " in London.