The Decepticons were the most feared faction on Cybertron during the Great War, committing the majority of the atrocities that took place during the conflict. Originally a small splinter group of the Ascenticons, calling themselves the Decepticons as a nod to the corruption and deception of the Cybertronian elite. They were originally led by the revolutionary writer Megatron and after she was ousted from the Ascenticons, Termagax, who became the co-leader of the organization. Under her guidance, the Decepticons grew, becoming champions of peace and unity and gaining numerous allies from all over Cybertron. However history repeated itself again and eventually, she was ousted from the group after the start of the Great War and Megatron gained full control of the organization. Shortly afterwards Megatron took over the Ascenticons after killing the Ascenticon leader Legonis. He then absorbed the Constructicon Clan and Seacon Syndicate into the organization, making the Decepticons one of the most powerful factions on Cybertron. From there, the Decepticons nearly overran the planet and the Great War soon left the planet and spread across the galaxy. Towards the end of the Great War, Megatron was overthrown in a coup by Shockwave due to his ineffective leadership. However, this created a power vacuum within the faction as Megatron was one of the few things holding them together. This caused a civil war to break out among the Decepticons, creating hundreds of splinter groups in the process. Eventually, Shockwave managed to take control of the faction, though at this point, it was too late. The Decepticons were merely a fraction of their previous strength and were easily routed across the galaxy by the Autobots. Shortly thereafter, Shockwave signed a peace treaty with the Autobots, allowing him to control Cybertron while also allowing the Autobots to focus on the remaining splinter factions. Of these splinter factions, the Destrons and Predacons remain the strongest.

Community content is available under CC-BY-SA unless otherwise noted.