How to avoid excommunication?

The Pope seems to slap that on me whenever I invade territory occupied by a Christian nation. Well first he asks me to withdraw my attack and I do. But a few years later I STILL get excommunicated for my 'agression towards fellow Christians.' This usually results in my getting pissed off and obliterating the Papacy. :charge: What is it that he wants anyway? Do I have to make peace with the other country?

To avoid excommunication, you have to withdraw from the territory and send a diplomat to arrange a ceasefire - otherwise you are still at war. If you do not get that ceasefire you will get excommunicated.
But here is a clever ploy, declare war on one faction and then on another immediately, followed by a ceasefire on the first faction. The computer can only keep track of one excommunication at a time and so does not recognise the second war and you can obliterate the faction at your leisure. I would not recommend fighting the Pope. His faction always reappears with massive armies and you end up having to garrison central Italy with a large army just to keep him under control. Why not use the Pope instead. Strip a province of defences, wait for your neighbour to invade and then crush him when he is excommunicated.

Actually, he gives you two years to stop your agression, so you have one more turn to assault any castles in the provinces you just took - then you can keep them as long as you don't attack the other faction for ten years. You can remain at war with them during that time, but you can't attack them. At the end of ten years they are likely to attack you if they have any fight left in them - if you are patient you can chew up whole empires by taking a bite every decade or so - have done this to Spain and HRE many times.

Sometimes they will attack you and get excommed themselves - then you can get medeval on their ass.

Note that when the pope dies all excommunications are void. So if you really want, wait until he is old and you will only be excommed for a short time. Or have a couple good assassins ready....

You don't need to get a ceasefire to avoid excommunication (which is fortunate, since AI factions will rarely agree to a ceasefire). In my current Italian campaign, I've been in a cold war with the English for years after having received the Papal warning, without being excommunicated.

After you receive the warning, you have one more year in which to launch attacks and/or withdraw from castles you are sieging. Thus you must either immediately launch your castle assaults, or withdraw and give up your newly conquered lands.

After that, you cannot make any aggressive military moves against the nation you have been warned against attacking. This includes naval attacks; it also includes attempting to break sieges on your own castles (even a sally is considered an attack). You can still use assassins. This state of affairs continues for ten years, of course.

Note that your enemy can still attack you without fear of Papal retaliation, unless he controls far more territory than you. (I think he'll only get excommunicated if he's twice your size.) The Pope will only protect the weaker faction.

As others have noted, only one warning can be in effect at a time (however, I have seen multiple excommunications at the same time). Thus, if you attack one faction and get warned, you can then proceed to attack other Catholic factions at will, and the Pope will not bother you. Just make conquests elsewhere for ten years, then resume your earlier war.

One more observation: it seems to me that excommunication is really not that bad. The only time it's become a serious problem for me is during one English campaign in which my king was excommunicated at a young age, and the excommunication dragged on for a long time. Loyalty started dropping all over the kingdom and I had to send my king to a suicidal death - but by then, he was already very old.

Everything that is said about excommunications is correct and is in the manual as well. But I have had the same problem as Serrvs many times. You invade a province, do what you can in the two years and then withdraw. But you still get excommuncated. I have even abandoned the province in a year and had no 'contact' with the enemy and still been excommunicated. So now I always try for a ceasefire even if I do not get it, it seemd to help. It is frustrating when the game does not behave quite as it should.

Excommunication can be a big problem if you get your zeal up.

Zeal can be your ally aswell. If you play a smaller catholic faction, leave the HRE alone for a century or so until its gobbled up some more territory, then move inquisitors in but keep them moving around so that they only increase zeal instead of burning people, provoke an attack and get them excommunicated. Thier empire will start to crumble as rebels pop up and every catholic faction on their border takes a bite. All you have to do is grab a peice.
It is difficult to get them excommed, Ive only worked this once, as the Spainish and I kept my empire small once Id dealt with the Almohads. doubled its size once id used all the spare crusades I had sitting around on the HRE