Ab urbe condita

Behind them were the standards under which were stationed fifteen companies, which were divided into three sections called vexillae, the first section in each was called the pilus, and they consisted of 180 men to every standard (vexillum). The first vexillum was followed by the triarii, veterans of proved courage; the second by the rorarii, or “skirmishers,” younger men and less distinguished; the third by the accensi, who were least to be depended upon, and were therefore placed in the rearmost line.

When the battle formation of the army was completed, the hastati were the first to engage. If they failed to repulse the enemy, they slowly retired through the intervals between the companies of the principes who then took up the fight, the hastati following in their rear.

The triarii, meantime, were resting on one knee under their standards, their shields over their shoulders and their spears planted on the ground with the points upwards, giving them the appearance of a bristling palisade.