Long story short, I built up a large empire from Ithaca into Thrace. I had intended to keep it simple and make the extent of my conquests be a single mainland province, but the damned Thracians declare war every other turn and my only hope of surviving the endless waves of heroes and enemies is to capture their money-makers. It doesn't seem to work, though, as they can field an enormous amount of troops (skirmishers, so every battle takes at least ten minutes to finish as my men chase the last troops down and corner them) despite having few provinces left.
I know this is a fault of the RTW AI, but every time I sign a peace treaty they declare war again within three turns. Can I do anything, or do I have to massacre every single one of them before they give up? No other factions have this fanatical need to attack me.