Quote Originally Posted by Ironsword
I've had the message "Your crusade is disbanded as the lands are now back into the hands of the Catholics etc.etc." This doesn't count as a failed crusade does it?
I do not know for sure if the loss of influence is exactly the same as if the crusade had been destroyed but I am postive that there is at least some loss of influence involved. Got rebellions as a result of such "failed" crusades and caused a few to the AI by getting the target province first.

Note that getting the province before the crusade gets there does not always make it disappear ... A few times I have seen the crusade keep on going nevertheless. Once it got to its target, you get a message asking you to handover peacefully the province to the [faction] who are on mission for God. If I remeber correctly if you tell them to get lost, you have battle on your hands and get ex-communicated. If you accept you loose the province and all your army made prisoner (not 100% sure about the emprisonement bit - perhaps it was due to the fact that there was nowhere to retreat to).