
Originally Posted by
Vlad Dracul
In MIITW allies exist with one purpose only: to betray you!
Without warning, sometimes for no reason (you have a good overall reputation, good relations with the attacker, didn't cross their territory, didn't spy/assassinate/vote the wrong cardinal for Pope, don't have any relations with their arch enemy etc.), other times following a pervert logic.
I know it sucks, but that's the game and the only thing you can do is to keep in mind that everyone can attack you and be prepared.
Also, you gotta be aware of the fact that there are several "trap provinces" on the map and if you take one of those, expect trouble with the factions that also desire it, regardless of the diplomatic treaties.
The pervert part, often the God damn Council of Nobles gives you missions to take those particular provinces!
I thought those guys are on my side, but no! They sure aren't.
Just one example of "trap provinces", Dijon, who is wanted by HRE, France, Milan and whoever will get to border that province later in the game (I saw Danemark owning it, Spain, Portugal, hell, even Venice!).
Remember, be prepared!