For years, a growing Separatist movement led by Count Dooku has threatened to split the Galactic Republic. Despite the best efforts of Senators like Padmé Amidala, there is no peaceful resolution.
Jedi intelligence reveals that the Separatists have turned to the Trade Federation and the various commerce guilds for support, and are preparing their vast droid armies for war. Acting on these alarming events, the Senate votes to give Supreme Chancellor emergency powers. He places the Jedi in command of the powerful clone armies of the Republic, and the Clone Wars erupt on the barren world of Geonosis.
Dooku escapes the battle, and soon thousands of other worlds soon join his forces.