About three throusand years ago speakers of Iranian languages moved into the area--on the east side of the Zagros, and spread eastward in subsequent centuries. The ones in Fars spoke Old Persian, the ancester of modern Persian. However, msot elite tasks were done using Aramaic, a Semitic language. Later Aramaic largely gave way to Hellenistic Greek, and then to Parthian, the first Iranian adminstrative language. After Greek rule ended, Old Persian evolved into Middle Persian, also called Pehleve or Pazand, especially under the influence of Arabic. This influence became more manifest in the modern Persian of the last few centuries.