For centuries the indigenous population exerted considerable influence on Greek settlers, but after the 4th century BC this population quickly started to become Hellenized. Very little is known about Pisidia prior to the 3rd century BC, but there is quite a bit of archeological evidence that dates to the Hellenistic period. Literary evidence, however, including inscriptions and coins are limited. During the 3rd and 2nd centuries BCE, native regional tongues were abandoned in favor of koine Greek and settlements began to take on characteristics of Greek "polis".