The style of fighting used by peltasts originated in Thrace and the first Greek peltasts were recruited from the Greek cities of the Thracian coast. On vases and other images they are generally depicted wearing the costume of Thrace including the distinctive Phrygian cap. This was made of fox-skin and had ear flaps. They also usually wear patterned tunic, fawnskin boots and a long cloak called a zeira decorated with a bright, geometric, pattern. However, many mercenary peltasts were probably recruited in Greece. Some vases have also been found showing hoplites (men wearing Corinthian helmets, greaves and cuirasses, holding hoplite spears) carrying peltes. Often, the mythological Amazons (women warriors) are shown with peltast equipment.
Peltasts gradually became more important in Greek warfare, in particular during the Peloponnesian War.
Xenophon in the Anabasis describes Peltasts in action against Persian cavalry at the Battle of Cunaxa in 401 BCE where they were serving as part of the mercenary force of Cyrus the Younger. In [1.10.7] 'Tissaphernes had not fled at the first charge (by the Greek troops), but had charged along the river through the Greek peltasts. However he did not kill a single man as he passed through. The Greeks opened their ranks (to allow the Persian cavalry through) and to proceeded to deal blows (with swords) and throw javelins at them as they went through.' 'ho gar Tissaphernês en têi prôtêi sunodôi ouk ephugen, alla diêlase para ton potamon kata tous Hellênas peltastas: dielaunôn de katekane men oudena, diastantes d' hoi Hellênes epaion kai êkontizon autous'. 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 traditional hoplite equipment and would have been more readily available to poorer members of society. The Athenian general Iphicrates destroyed a Spartan phalanx in the Battle of Lechaeum in 390 BCE, using mostly peltasts. In the account of Diodorus Siculus, Iphicrates is credited with re-arming his men with long spears, perhaps in around 374 BCE. This reform may have produced a type of "peltasts" armed with a small shield, a sword, and a spear instead of javelins. Some authorities, such as J.G.P. Best, state that these later "peltasts" were not truly peltasts in the traditional sense, but lightly-armored hoplites carrying the pelte shield in conjunction with longer spears--a combination that has been interpreted as a direct ancestor to the Macedonian phalanx. However, thrusting spears are included on some illustrations of peltasts before the time of Iphicrates and some peltasts may have carried them as well as javelins rather than as a replacement for them. As no battle accounts actually describe peltasts using thrusting spears it may be that they were sometimes carried by individuals by choice rather than as part of a policy or reform. The Lykian sarcophagas of Payava from about 400 BCE depicts a soldier carring a round pelte but using a thrusting spear overarm. He wears a pilos helmet with cheekpieces but no armour. His equipment therefore resembles Iphicrates's supposed new troops. 4th century BCE peltasts also seem to have sometimes worn both helmets and linen armour.
Alexander the Great employed peltasts drawn from the Thracian tribes to the north of Macedonia, particularly the Agrianoi. In the 3rd century BC peltasts were gradully replaced with thureophoroi. Later references to peltasts may not in fact refer to their style of equipment as the word peltast became a synonym for mercenary.
When fighting other types of light troops, peltasts were able to close more aggressively as in melee they had the advantage of possessing shields, swords and helmets.