What is "hastati"

Hastati (singular: Hastatus) were a class of infantry in the armies of the early Roman Republic who originally fought as spearmen, and later as swordsmen. These soldiers were the staple unit after Rome threw off the Etruscan rule. They were originally some of the poorest men in the legion, and could afford only modest equipment—light chainmail and miscellaneous equipment. The Senate supplied their soldiers with only a short stabbing sword, the gladius and their distinctive squared shields. The Hastati soldier was typically equipped with these, and several soft iron tipped throwing spears called pila. This doubled their effectiveness, not only as a strong leading edge to their maniple, but also as a stand-alone missile troop. Later, the hastati contained the younger men rather than just the poorer, though most men of their age were relatively poor. Their usual position was the first battle line. They fought in a quincunx formation, supported by light troops. The enemy was allowed to penetrate the first battle line consisting of hastati, then the enemy would deal with the more hardened, seasoned soldiers, the principes. They were eventually done away with after the Marian reforms of 107 BC.