I recently tried an experiment to see what all the mega events that might occur with my playstyle are. After enabling cheats, I loaded several different saved games and used the cheat to summon a mega event (ctrl-Y) repeatedly. I saw a fairly diverse set, but rather to my surprise, I never saw, despite loading several very different games, the Peacekeepers. What particularly surprises me about this is that, in a number of games, there are multiple wars raging, with ships in many different influence zones not belonging to their owner. This is what I always believed triggered the Peacekeepers.

I've been attempting for some time to figure out just what factors relate to most mega events, but the Peacekeepers' "cause" has me stumped. For anyone who's encountered them, what kind of a game were you playing?