From 1984's sci-fi classic The Terminator, through seminal 1991 action movie Terminator 2 and the disappointing T3, all the way up to the middling Terminator Salvation and Genisys, the Terminator franchise has had its share of ups and downs. It's gone from James Cameron, to Jonathan Mostow and - oh god - McG, from Schwarzenegger in his prime to Schwarzenegger in old age, and from science fiction to action movie to war movie and back again. As a result of the changing nature of the films, not to mention the various clashing egos that have come to work on them, the Terminator franchise is a saga that's accumulated one of the most fascinating behind-the-scenes stories. With the series having run for 31 years, that story's also one of Hollywood's farthest-reaching franchise tales. And it all grew out of an idea of James Cameron's that was originally rejected, by the very studio that produced the latest in the series: Terminator Genisys, a film which Paramount Pictures has primed as the beginning of a new trilogy. Over the years, the Terminator series has lost its creator to more lucrative projects, lost Arnold Schwarzenegger to a political career, been the cause of an epic Christian Bale rant, regained Schwarzenegger, and attempted to reboot twice in a decade. That much you already know; here are 20 mind-blowing facts you never knew about the Terminator franchise.