Darth Vader is the central antagonist in George Lucas' original Star Wars trilogy and his final prequel, Star Wars Episode III: Revenge of the Sith. In the original trilogy, George Lucas depicts Darth Vader as a fearsome cyborg who acts as the supreme commander of the brutal Galactic Empire. Throughout the films, Vader oppresses the galaxy and hunts down the members of the Rebel Alliance in the service of his master, Emperor Palpatine. In Star Wars Episode VI: Return of the Jedi, the series' final chronological installment, Vader redeems himself by killing Palpatine and saving his son Luke, sacrificing himself in the process. In the prequel trilogy, Lucas shows Vader as his former self, Anakin Skywalker, a slave boy who eventually becomes a Jedi Knight, and later, a hero in the Clone Wars. Palpatine manipulates Anakin into betraying the Jedi, and Anakin falls to the "dark side" of the mystical Force.