Julian the Apostate

Religion is often accused of causing most of the wars in history.  This is hardly fair.  People are quite capable of picking fights without any divine inspiration, even if religion is a handy justification to cover your true motives.  And religious leaders sometimes take a role in solving problems, which evens up the balance sheet a bit.  But the charge is not totally groundless. Religion itself can be the problem, and the religious trauma of the late Roman Empire is the textbook case.