Megatronus Prime was one of the original seven Primes scattered throughout the galaxy looking for planets where they could build Solar Harvesters. These massive machines create Energon, the vital energy of Transformers, by destroying suns and were activated by an artifact known as the Matrix of Leadership. The Dynasty of Primes had one rule: Solar Harvesters were not to be built in systems which contain life. Megatronus, believing that the Cybertronians were the ultimate race and destined to rule the universe and due to his contempt for the human race, chose to ignore this rule and arrived on Earth in 17,000 B.C., where he began construction of a new Solar Harvester. To assist him, Megatronus assembled an army of like-minded Cybertronians who called themselves “Decepticons”. Identifying themselves with a symbol based on Megatronus’s fearsome visage, the Decepticons built the Harvester in prehistoric Egypt, where they slaughtered any humans who discovered the Harvester. Learning of his betrayal, the other Primes launched an assault on the Decepticon forces and although they were unable to kill Megatronus; the Primes succeeded in capturing and imprisoning him back on Cybertron before sealing the Matrix within a tomb made of their own bodies, sacrificing themselves to help save Earth and humanity.

As a result, Megatronus, now the Fallen, became the first Decepticon and the true founder and leader of the Decepticons (as Megatron accepts the Fallen as his master), and all future Decepticons would wear an insignia which was similar to the Fallen’s face.