A
battle cry is a yell or chant taken up in
battle, usually by members of the same combatant group. Battle cries are not necessarily articulate, although they often aim to invoke
patriotic or religious sentiment. Their purpose is a combination of arousing
aggression and
esprit de corps on one's own side and causing
intimidation on the hostile side. Battle cries are a universal form of
display behaviour (i.e.,
threat display) aiming at
competitive advantage, ideally by overstating one's own aggressive potential to a point where the enemy prefers to avoid confrontation altogether and opts to flee. In order to overstate one's potential for aggression, battle cries need to be as loud as possible, and have historically often been amplified by acoustic devices such as
horns,
drums,
conches,
carnyxes,
bagpipes,
bugles, etc. (see also
martial music).