Count Dooku/Darth Tyranus
Dooku had studied the ways of the Force for almost eight decades, becoming one of its most powerful practitioners, though his ultimate loyalty was not to the structured protocols of the Jedi order, but rather to his own intuitions and ideals. His strong sense of independence concerned many, and even his mentor, Yoda, had difficulty reining him in.
Bronzium busts of many great Jedi Masters line the walls of the Jedi Temple’s Archives Room. Of these Masters, twenty abandoned their lives of service to walk other paths. Count Dooku was by far the most tragic, for in leaving the Jedi Order he joined the ranks of the Sith.
Although he never sat on the Jedi Council, Dooku earned the respect of his peers through his expertise as a lightsaber instructor and his principled stand on government. Dooku believed that the Republic had grown corrupt, and that the Jedi should no longer serve such a rotten system. Many on the Council sympathized, but argued that to cut ties with the Republic would be to abandon the citizens they’d sworn to protect.
After the Battle of Naboo, Dooku announced his resignation from the Jedi Order, then disappeared. None of his fellow Jedi knew where he’d gone. He first reemerged on Raxus Prime, complete with a fiery rhetoric lambasting the Senate and the Jedi order's complacency in the visible erosion of morals and ideals of the Republic. Since that time, his base of operations became mobile, as he traveled from world to world, fomenting secession and leading the Separatist movement that soon developed an alarming cohesion.
It is yet unknown when exactly Dooku abandoned himself to the dark side of the Force, though he had apparently experimented with forbidden lore in the past. Rumors abound that Dooku was familiar with Sith teachings stored within a dark Holocron kept in the Jedi Archives.
Dooku had begun training with Darth Sidious. He’d come to believe that through the dark side, he could shape the galactic order to fit his vision. Sidious, having just lost Darth Maul, knew he didn’t have the time to train a new Sith apprentice from infancy, and was happy to have snared such a venerable Jedi.
Renamed Darth Tyranus in the Sith tradition, Count Dooku recruited the bounty hunter Jango Fett to serve as the template for a secret clone army that would be grown on the planet Kamino. He began stirring up anti-Republic sentiment among the outlying systems. Then, Dooku eventually came out of his self-imposed exile. Alleging that Supreme Chancellor Palpatine had done little to curb governmental corruption, Dooku called for systems to create a republic of their own design. Nearly two hundred systems walked out to join him. The Republic, protesting the illegality of the movement, began what would become a two-year debate over the legitimacy of the Confederacy of Independent Systems.
When terrorist bombings began plaguing Coruscant, many Senators blamed the secessionist and debated creating a standing military force. Meanwhile, as the Republic struggled with the concept of raising an army, Dooku simply bought one. He met with representatives from the Trade Federation, Commerce Guild, Inter-Galactic Banking Clan, Techno Union, and Corporate Alliance, promising economic concessions that would line their pockets. In exchange he received their war machines.
The Jedi Knight Obi-Wan Kenobi discovered the treasonous meeting and warned the Republic, but not without being captured. Dooku met with Kenobi in the Geonosian dungeons, and revealed to Obi-Wan the truth about the Republic -- that it was, in fact, becoming increasingly under the control of Darth Sidious. Distrusting of Dooku's words, Obi-Wan refused to believe and refused to join Dooku in rooting out the corruption.
Kenobi was soon joined by Anakin Skywalker and Padmé Amidala, who had come to Geonosis in an ill-fated attempt to rescue him. Dooku placed the three captive heroes in an execution arena, but their deaths were staved off by the timely arrival of Jedi reinforcements.
The droid armies of the Separatists engaged the Jedi, and later the newly crafted Clone Army of the Republic. Dooku attempted to escape but was intercepted by Anakin Skywalker and Obi-Wan Kenobi. The two Jedi challenged Dooku to a lightsaber duel, but Dooku's masterful skills in old-style lightsaber combat made short work of the younger combatants. As they lay wounded, another Jedi entered into Dooku's secret hangar.
The Jedi Master Yoda confronted Dooku. The two engaged in a titanic struggle of Force powers, neither besting the other. It came down to a contest of lightsabers. In a blurring tangle of speed and light, the two masters of the Force dueled. Unable to find an advantage, Dooku distracted Yoda by endangering Kenobi and Skywalker with a toppling crane. As Yoda used the Force to save his fellow Jedi, Dooku fled.
Dooku escaped, with the Jedi aware of his succumbing to the dark side, but yet still unaware of his Sith allegiance. Aboard his exotic interstellar sail ship, Dooku traveled to a decrepit warehouse district on Coruscant. There, he met with his master, Darth Sidious, and delivered the good news. The Clone Wars had begun.