Excommunication questions

I had a question about who the pope threatens and tries to excommunicate during a war between two catholic factions. My theories were:
A: Warns both
B: Warns agressor
C: Warns member with lower papal standing
D: warns faction winning war
E: Warns more powerful faction
but in 4 wars in 3 games (Medium), all started by the computer, I came across the following:
Theory A
Once, the other faction was excommunicated before I recieved any warnings
Theory B
In the other 3 wars, despite the other faction beginning war, I recieved threats
Theory C
three wars corresponded to this theory
Once, with perfect standing pre-war, and pope of my faction, recieved threats
Theory D
Two wars supported this theory, two opposed
Theory E
Three wars supported this theory, one (see theory A contradiction) opposed.

So, is there any logic behind the pope, or does he threaten excommunication randomly?

I'm pretty sure that you're partially correct with Theory B. However, it seems to me that you can fight the other Catholic factions to no end as long as you confine it to your territory.

If I control Caen and the French attack me in my province, they seem to get a warning, because the next time they attack, their standing with the Pope goes down. As long as I control Caen, I can attack French units on my lands without any warnings or penalties.

However, if the French take Caen, it is considered to be their province. When I lay siege to Caen to try to get it back, I get the warning, and then immediate excommunication if I follow through with the assault next turn. Probably something similar if I attack their free-roaming armies in that province, too.

This is why artillery is so important. Once another Catholic faction has attacked me, I move armies with heavy artillery to my borders. Usually they can reach and assault an enemy city in one turn's march. After I take the city/fortress, the province is considered to be mine and I can hunt down the AI's armies in that province with no penalty.

Of course, whoever starts a war by attacking first gets the warning - but it's always just a matter of time before all of your neighbors attack, and you will never have to wait too long.

[QUOTE=Blackboots]

If I control Caen and the French attack me in my province, they seem to get a warning, because the next time they attack, their standing with the Pope goes down. As long as I control Caen, I can attack French units on my lands without any warnings or penalties.

[/QUOTE

You cant attack them. They have to initiate the attack. Example; a french army comes to your province and attacks you, or lays siege to your city you can then attack back. However if they just show up on your land standing about and you attack them, you could get a warning from the Pope. I've had this happen to me plenty of times.

Its important to let the AI enemy attack you first to avoid Papal warnings. Personally I think there shouldnt be a penalty from the Pope if a enemy unit/s in on your land but thats not the way it is. They come onto your turf they should be held in the wrong. Not you.

If the enemy has had its faction excommunicated then you can attack them all you want wherever they are.