Count Dooku is a fictional character from the Star Wars universe. In the prequel films, he is played by Christopher Lee, and is voiced by Corey Burton in the video games and the animated series Star Wars: Clone Wars. He is the main villain of Star Wars Episode II: Attack of the Clones and a supporting villain in Star Wars Episode III: Revenge of the Sith. He also plays a substantial role in the "Expanded Universe" of novels, comic books, and video games.
Yoda was his master while Dooku was a Jedi. Count Dooku is a powerful Jedi Master and Sith Lord, the successor of Darth Maul. His Sith title is Darth Tyranus.
Dooku captures Obi-Wan Kenobi (Ewan Macgregor) on Geonosis. Dooku tells Kenobi that he is attempting to save the Republic from the influence of a Sith Lord named "Darth Sidious", whom he claims has control of a large number of senators. He also states that he was sad at the loss of Kenobi's former master and Dooku's former apprentice, Qui-Gon Jinn. Kenobi refuses to join Dooku and is sentenced to death.
A clone trooper and Jedi force rescue Kenobi, along with Anakin Skywalker (Hayden Christiansen) and Padme Amidala (Natalie Portman). Skywalker and Kenobi chase Dooku and have a lightsaber fight in which Kenobi is incapacitated and Anakin loses his right arm. Yoda, Dooku's former master, then fights the Sith Lord. Unable to defeat Yoda, Dooku distracts him by trying to make a large pillar fall on Kenobi and Anakin; Dooku escapes from Geonosis as Yoda is busy saving the two Jedi. Dooku flies to Coruscant and delivers to Sidious the blueprints for the Geonosian-designed Death Star.
In the opening of Revenge of the Sith, Skywalker and Kenobi are sent to rescue Palpatine from Separatist leader General Grievous's flagship. In the novelization of Revenge of the Sith, Dooku plans to kill Kenobi and then surrender to Skywalker: Palpatine tells Dooku that without Kenobi's influence, Anakin will be easily turned to the dark side. However, Skywalker severs Dooku's hands; at Palpatine's urging, the Jedi then decapitates Dooku.
In Sean Stewart's Yoda: Dark Rendezvous, he attempts to trap his former Master by offering to negotiate an end to the war; This novel reveals that Dooku had always resented his parents for giving him away to the Jedi Order.
In James Luceno's Labyrinth of Evil, he engineers General Grievous' transformation into the Separatists' cyborg commander, and trains him in lightsaber combat. He then schemes with Sidious to invade Coruscant — thus setting the stage for Revenge of the Sith — as a ploy to kill Obi-Wan Kenobi and initiate Anakin Skywalker into the Sith (Dooku is, of course, unaware that Sidious truly plans to sacrifice him).