Gladiatorial combat
One of the less reputable aspects of Pre-War Cybertron was the fact that it had gladiatorial combat. Though many of these games were officially illegal, they often thrived, with Transformers battling each other to the death. Many government officials new of this, but they often turned a blind eye to it.
They should have paid better attention, for within these arenas, Megatron first arose...and found many similarly minded individuals.
Fiction
G1 cartoon continuity
Millions of years in the past, when Cybertron was still a Quintesson-ruled factory world, the planet's robot slaves were often forced to battle each other in gladiatorial combat for the amusement of their masters. Some of the robots forced to compete in these sadistic games grew tired of it, and attempted to fight back against their masters. Although this initial revolt failed, it would plant the seeds of rebellion that would eventually prove successful, and one of the participants would go on to hold the Matrix of Leadership. FFoD, Part 4
Dreamwave continuity
There were several gladiatorial combats staged in city-states far from Iacon, such as in Kaon. For some, such as Grimlock, it was a good outlet for anger and aggression. Megatron was a participant of these games. As his victories mounted, he realized that they were a simple conspiracy by the Council of Ancients to keep the masses distracted. Megatron began using the matches to find similarly minded Transformers. For over half a million years, Megatron used the games to recruit the Decepticon army, bribing Emirate Xeon to remain quite. Finally, however, they struck. The War Within
IDW continiuty
After their prison riot and escape, Megatron, Rumble, and Frenzy escaped to Kaon, where they joined Clench's illegal gladiatorial circuit. Megatron's star began to rise, attracting the attention of Sentinel Prime and Senator Ratbat. Megatron Origin, Part 2
