A question of honour

[_Tristan_]

"Untrustworthy" refers mostly on backstabbing your allies. You should never attack allied faction, if you don't want to become "Untrustworthy", you must first cancel the alliance.

Even cancelling an alliance out of the blue will get a rep hit... If you ever intend to go at war with someone, either do not ally (ever !!) or force them to strike first...

Cancelling diplomatic agreements (except for when you have to drop an ally due to a declaration of war).

Same here, being forced to choose between two of your allies going to war will almost always get you a rep hit (from my own experience) which is why you should refrain from allying with parties that are sure to go to war (like Byz and Turks for exemple...)

[Zaleukos]

Same here, being forced to choose between two of your allies going to war will almost always get you a rep hit (from my own experience) which is why you should refrain from allying with parties that are sure to go to war (like Byz and Turks for exemple...)

It does go down, but I got the impression that breaking an alliance that way is less costly in reputation than cancelling the alliance in the diplomacy screen (and way less costly than declaring war on your ally). When I want to attack an ally I usually try to order a crusade against them, wait for another ally to attack them, and only join the crusade only after I had to choose which alliance to keep. This seems to give a much smaller reputation hit than joining the crusade when still allied to the crusade target.

If the pope is young I also use crusades to complete the stupid "break alliance with excommed faction" missions, which otherwise are fairly costly in terms of reputation.

The difference in the first case could of course stem from the difference between the penalties for "cancelling alliance + declaring war" and "declaring war on ally".

Unfortunately it's largely guesswork on my part as I dont have a numerical value for reputation, but only the crudely discretised value in the diplomacy window...