History of the Peloponnesian War

After this they joined battle, the Argives and their allies advancing with haste and fury, the Lacedaemonians slowly and to the music of many flute-players—a standing institution in their army, that has nothing to do with religion, but is meant to make them advance evenly, stepping in time, without breaking their order, as large armies are apt to do in the moment of engaging.

Just before the battle joined, King Agis resolved upon the following manoeuvre. All armies are alike in this: on going into action they get forced out rather on their right wing, and one and the other overlap with this their adversary's left; because fear makes each man do his best to shelter his unarmed side with the shield of the man next him on the right, thinking that the closer the shields are locked together the better will he be protected. The man primarily responsible for this is the first upon the right wing, who is always striving to withdraw from the enemy his unarmed side; and the same apprehension makes the rest follow him.