Darth Vader is the principal villain of George Lucas's Star wars saga. The character was ranked as the third greatest villain in American film history by the American Film Institute. With his "skull/samurai" helmet and imposing appearance, the character has entered the English lexicon to refer to anyone perceived as evil or diabolical. In recent times, the character has become synonomous with dictatorial rule.
The actor James Earl Jones provided the voice of Darth Vader in the four movies that the "suited" character has been featured. David Prowse was the physical actor in Episodes IV through VI and Hayden Christensen played the character in Episode II and III.
In episodes IV, V, and VI, Vader serves the Emperor Palpatine. He oversaw constrction of both Death Stars. At the end of Episode VI, his dying act is his redemption from the Dark Side, with the help of his son, Luke Skywalker.
In the prequel trilogy, Vader starts as an innocent young child of about eight (Anakin Skywalker). As he grows, he begins to be seduced by the Dark Side of the Force. When he has a vision that his mother is being tortured, and later when he sees her die, he kills an entire camp of Tusken Raiders. Later, when he has a vision about his wife, Padme, dying in childbirth, he turns to the Dark Side to try to save her. Ironically, his Force choke (Episode III) ends up being part of what killed her.