shortage of cavalry in the army of the early to mid Republican army, the velites were also used as scouts. They did not have a precise formal organisation or formation. Heavy infantry: This was the principal unit of the legion. The heavy infantry was composed of citizen legionaries that could afford the equipment composed of an bronze helmet, shield, sword, armour and pilum, a heavy javelin whose range was about 30 metres. After the Second Punic War, the preferred weapon for the hastati and principes was the gladius, a short sword. Their hobnailed sandals (caligae) were also an effective weapon against a fallen enemy. Prior to the Marian reforms (see below), the heavy infantry was subdivided, according to experience, into three separate lines of troops: The hastati (sing. hastatus) consisted of raw or inexperienced soldiers, considered to be less reliable than legionaries of several years' service. The Hastati were placed at the front for several reasons. One reason is the city of Rome could ill-afford to lose experienced soldiers, so they put the greenest soldiers at the front. If they survived, the hastati would gain invaluable experience. Another reason is if the newest soldiers succumbed to battle nerves and broke and tried to run, then there were experienced soldiers behind them to stiffen their resolve. The principes (sing. princeps) These were the more experienced soldiers, often better equipped than the hastati, and having more experience on the battlefield, they would take up the second line in the battle in the event the Hastati failed or fled. They were the second wave in an early Republican Legion before the military reforms of Marius. The triarii (sing. triarius) were the veteran soldiers, to be used in battle only in extreme situations; they rested one knee down when not engaged in combat. The triarii served primarily as reserves or barrier troops designed to backstop the hastati and principes, and were equipped with long hastae (spears) rather than the pilum and gladius (the hastati and principes stopped using spears in 387 BC). Thus armed, they fought in a phalanx formation. The sight of an advancing armored formation of triarii legionaries frequently discouraged exultant enemies in pursuit of retreating hastati and principes troops. Ad triarios redisse – To fall back upon the triarii – was a Roman idiom meaning to use one's last resort. Each of these three lines was subdivided into (usually ten) chief