In 113 BC, the Iranian Parthians conquered Dura-Europos, and held it, with one brief intermission, until 165 AD, when it was taken by the Romans. The Parthian period was a phase of expansion at Dura Europos—an expansion favored by abandonment of the town's military function. All the space enclosed by the walls gradually became occupied, and the installation of new inhabitants with Semitic and Iranian names alongside descendants of the original Macedonian colonists contributed to an increase in the population, which was a multicultural one, as inscriptions in Greek, Latin, Hebrew, various Aramaic dialects (Hatran, Palmyrene, Syriac), and also Middle Persian, Parthian, and Safaitic testify. In the 1st century BC, it served as a frontier fortress of the Parthian Empire.