According to the cartoon continuity, the Decepticons were descended from non-sentient military hardware created by the Quintessons. The Decepticons coexisted peacefully with their household/transport robot decended cousins, the Autobots for a while after ousting the Quintessons from Cybertron. Owing to their military backing, however, the Decepticons became cruel and ruthless, wishing to control Cybertron and destroy the Autobots. This led to the three Cybertronian Wars