Sith is a term applied to certain characters in the Star Wars universe capable of using the 'dark side' of the Force. In the Star Wars films and much of the Expanded Universe they are the main antagonists. Star Wars creator George Lucas took the name 'Sith' from Edgar Rice Burroughs' John Carter of Mars series in which the sith are giant, venomous, hornet-like insects that are difficult to kill. The first use of the word 'Sith' is in the Star Wars novelization for Star Wars Episode IV: A New Hope, as a title for Darth Vader, the 'Dark Lord of the Sith.' The Sith are not formally introduced or mentioned as such on-screen until Star Wars Episode I: The Phantom Menace, the fourth film to be released. The Star Wars series began with the film Star Wars, which was released in 1977.
Contributions by Jon Hart, John-1107, and Marudubshinki.