I doubt that many of those battles were fought for Religious reasons. More likely, as usual in these things, those that wage war for power, simply use religion as a means to inspire their followers to fight for them.
The only really sad thing, is that after all those centuries of blood-shed, people are still stupid enough to follow their Leaders by accepting and allowing themselves, to be coerced and misled into fighting for the same, bogus reasons.
Mankind Eh? Stupid breeding stupid.
