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
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
