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
Thracian warfare though this must not have been universal among them. The Triballi had adopted Celtic equipment. Another weapon, the sica was called "Thracian sword" (Ancient Greek,"Θρακικον ξίφος") though it did not originate from there, despite its popular usage (it was considered their national weapon). The sword's utmost origin was the Hallstatt culture and the Thracians may have adopted or inherited it. Greece affected Thracian warfare early on with the xiphos and other swords, Greek type greaves, breastplates, a variety of helmets and other equipment. During the Hellenistic period more Greek armaments were adopted. Seuthes had adopted a Greek tactic for a