Ahsoka Tano, a Togruta female, was the Padawan learner to Anakin Skywalker and a hero of the Clone Wars. Alongside Anakin, she grew from headstrong student into a mature leader. But her destiny laid along a different path than the Jedi.
In the final days of the Republic, the galactic government had grown so huge and corrupt that any attempt at change required radical thinking and extreme actions. Outlying systems that saw no benefit from being part of the Republic despite paying heavy taxes, began to rebel. This undercurrent of disgust towards Coruscant was seized by a charismatic leader, Count Dooku. The former Jedi rallied together these worlds in a Separatist movement that saw the departure of thousands of systems from the Republic. When Dooku's alliance was secretly backed by corporate titans that offered their unlimited droid armies to the cause, the Separatists emerged as a major threat to the Republic, and the galaxy tipped towards full scale war.
Rather than use flesh-and-blood warriors, the Separatists prefer mindlessly loyal soldiers that are easily controlled. The soulless ranks of their armies are dominated by tall, thin B1 battle droids built as mechanical imitations of their Geonosian designers. Battle droids can be controlled by centralized command centers such as the Trade Federation’s enormous Droid Control Ships, or programmed for independent action. They often suffer programming glitches that manifest as personality quirks. Battle droids are dim-witted and no match for clone troopers or Jedi, but they weren’t designed to be smart – they were designed to overwhelm Republic civilians through sheer numbers, something they do very effectively.