Ancient Greek religious beliefs and practices greatly influenced or interacted with Greek warfare, generals and the individual combatants in battles. Yet in the modern scholarship of Greek warfare, such religious factors are a relatively neglected topic. This volume is written by ten international experts in Greek history, and seeks to draw attention to the role which the ancient Greeks of the Archaic and Classical periods believed their gods played in warfare - both wars between Greek states, and against barbaroi (barbarians), especially the Persians. Without an understanding of the Greek ideology of divine assistance prior to and during battle, the religious rituals surrounding Greek warfare are inexplicable. Only by coming to a realization that the ancient Greek attitude to the gods involved their unequivocal popular belief in a divine interest in human affairs, particularly in one of the most important spheres of Greek activity, warfare, can Greek warfare - as a system of cultural values working within a ritual context and framework - be understood. The attention paid to the appearance of the entrails of a beast sacrificed before battle, the abandoning of long-planned military campaigns due to earthquakes, the special devotion to deities of battle and war, and other ritual (in the religious sense) features of Greek warfare only make sense if the sacred acts and beliefs surrounding Greek warfare are examined in detail.