The equestrians, the highest social class of all, served in mounted units known as "equites". The first class of the richest citizens served as heavy infantry with swords and long spears (resembling hoplites), and provided the first line of the battle formation. The second class were armed similarly to the first class, but without a breastplate for protection, and with an oblong rather than a round shield. The second class stood immediately behind the first class when the army was drawn up in battle formation. The third and fourth classes were more lightly armed and carried a thrusting-spear and javelins. The third class stood behind the second class in battle formation, normally providing javelin support. The poorest of the propertied men of the city comprised the fifth class. They were generally too poor to afford much equipment at all and were armed as skirmishers with slings and stones. They were deployed in a screen in front of the main army, covering its approach and masking its manoeuvres.