Evidence suggests that the ancient Greeks engaged in siege warfare from the Bronze Age but our historical sources improve in the Classical period, when sieges appear with greater frequency. Thucydides felt that “war teaches men to be violent” (Thuc. 3.82.2) and few can deny that in the fifth and fourth centuries BC, sieges, death, enslavement, and forced exile were grim, though ever-present, possibilities as an outcome for a polis that went to war. The ancient Greek historian Xenophon makes it clear in the above quotation that the fortunes of the inhabitants of a successfully besieged polis were completely in the hands of the enemy. There were no conventions in place, no protocols established by the Greeks that set standards for what might be termed humanitarian treatment of the victims of war. In fact, the fortunes of the defeated were very often left to the discretion of the victorious general and their treatment varied greatly. Some army commanders, for example, refused to burn down houses or commit massacres and showed mercy to temple suppliants. They are often mentioned in the ancient sources as having htaken their religious duties seriously, such as taking sacrifices, obeying auspices and honoring oaths.
In fact, a close reading of the ancient sources suggests that the conquered frequently fared better if the opposing general held his religion in high regard. This paper argues that the religious piety, or lack thereof, of individual commanding officers in Classical Greek armies often served either to discourage or encourage, respectively, the committing of what might be termed by moderns as war atrocities in ancient Greek warfare.