Arians (Old-Persian Haraiva): ancient tribe, living in western Afghanistan (modern Herat). Not to be confused with the Aryans. The Arians were subjected to the Medians, and became a satrapy of the Persian Empire when king Cyrus subjected the Medians (550 BC). During the civil war in 522/520, the Arians seem to have remained quiet. Under Persian rule, the Arians started to live in towns; the Greek geographer Ptolemy (Geography 6.17.3) states that there were many towns and villages, and that there were nomadic tribes. The latter lived in the mountains.

In the last months of 330 BC, the Macedonian king Alexander the Great conquered Aria in pursuit of the last Persian leader, Bessus. He is credited with the building a town called Alexandria (modern Herat), but this was probably a Persian center of government.

After Alexander's death (in 323), Aria became a stable part of the Seleucid Empire -ruled by a Macedonian dynasty- for more than half a century. However, after 250, the neighboring countries Bactria and Parthia became independent from their Macedonian overlords. Aria became part of the new Bactrian kingdom, although the Seleucid king Antiochus III managed to extend his realm to the east between 208 and 190. His son Antiochus IV send a general, Eucratides, to do the same in 167, but the Parthian king Mithridates I outsmarted him and seized almost all Afghanistan. From now on, Aria was part of the Parthian Empire.