Peltast their ranks (to allow the Persian cavalry through) and proceeded to deal blows (with swords) and throw javelins at them as they went through. Xenophon's description makes it clear that these peltasts were armed with swords, as well as javelins, but not with spears. When faced with a charge from the Persian cavalry they opened their ranks and allowed the cavalry through while striking them with swords and hurling javelins at them. They became the main type of Greek mercenary infantry in the 4th century BCE. Their equipment was less expensive than that of traditional hoplites and would have been
Ancient Greek warfare undermanned. However, the lightly armored Persian infantry proved no match for the heavily armored hoplites, and the Persian wings were quickly routed. The Greek wings then turned against the elite troops in the Persian centre, which had held the Greek centre until then. Marathon demonstrated to the Greeks the lethal potential of the hoplite, and firmly demonstrated that the Persians were not, after all, invincible. The revenge of the Persians was postponed 10 years by internal conflicts in the Persian Empire, until Darius's son Xerxes returned to Greece in 480 BC with a staggeringly large army (modern estimates suggest between