What can cause Barbarian Uprisings?

[TwoBits]

thejeff said:
Provinces can revolt?
Are you sure? I don't think I've ever seen it. And I've had provinces sit well over a 100 unrest for many turns.

I only remember this ever happening to me once, and I sort of forget the nature of the event (I don't think there was any battle, but I'm not sure). So, whatever the circumstances of it occurring, I believe it's exceptionally rare. Then again, I generally prefer to play with positive luck scales, and try to keep unrest under control as much as possible...

In any event, barbarian raids, vine-men attacks, vampire rebellions, heck, even Bogus and Co., etc., seem to be way more common.