29. The Birth of the Flexible Legion and the Sword-Wielding Legionary
The Romans originally fought with spears in dense phalanx formations. They switched to a more spread out legion with sword-wielding legionaries because of the Samnite Wars, fought from 343 to 290 BC. Their Samnite enemies inhabited the Apennine Mountains south of Rome, and in that rough mountainous terrain, the dense phalanx proved to be unwieldy. By contrast, the Samnites were armed with swords and fought in flexible formations, with smaller subunits known as maniples (“handfuls”). They ran rings around the Romans, and dealt them a series of defeats that culminated in the surrender of an entire Roman army at the Caudine Forks in 321 BC. The Romans were a pragmatic lot, and often copied from others what worked. So they abandoned the phalanx and adopted the manipular system around 315 BC, and legions were broken into heavy infantry maniples of 120 men, in three ranks of 40 men.
Maniples were arrayed in three layers, based on experience and wealth – until the late second century BC, Roman soldiers paid for their own equipment. In front of them were the velites, or skirmishers, often the youngest and nimblest. The first heavy infantry line were the hastati, armed with short swords, a squared shield, the scutum, and throwing spears, the pila. Then came the princepes, prosperous men in the prime of their lives, who could afford decent equipment. Finally came the triari, the oldest and often wealthiest men, who could afford the best equipment. Armed with spears, they formed the last battle line. They were seldom used, battles were usually won by the soldiers ahead of them. They were only committed if things went wrong, and “it has come to the triarii” became a common Roman phrase to mean the need to use one’s last resort.