SirGrotius said:
I've had plenty of civil wars, consider yourself lucky that you've never had one. Does your leader have rivals?
Eh, I don't find them too bad. Sometimes even fun. But then, there were three times when I came close to losing, and two of them were because of civil wars. Once, as Rome I had engaged in a war with the Seleucids when my glorious German legion decided to take Rome and everything but the rest of Italy and march towards Apulia (the new capital), trying to crush the Dictator. Once, as Carthage, in a similar situation. The leader of my main army, sieging Rome and even taking it, decided to march on Carthage instead, taking Rome, a good deal of the Mediterranean and parts of Egypt with him.
The third time, as Massilia, I had to find out what it means to engage in a three front war on my own with no manpower. I had crushed Rome earlier (and allied again with them afterwards.

) and now was taking the various Gallic powers, while "engaging" in a war with the Macedonian alliance together with the Romans (though all Greeks loved me and at first seemed to rather fight Rome than anyone else). Exactly at that time Carthage, having taken almost all of Iberia, decided to attack me. I did get a white peace with them eventually, simply because I was persistent enough, and managed to get Rome into the war, but not without giving tribute to Macedonia for a desperately needed peace.
The AI may be stupid sometimes, but it does exploit weaknesses quite well once in a while.