From the foundation of the Kingdom, about B.C.255 to the Creation of the Empire by Mithridates or Arsaces VI, about B.C.174
Parthia, which in the earlier times of the Persian monarchy, formed a portion only of a large satrapy extending from the Iranic desert to the Jaxartes and from the Caspian to Samarcand, appears towards the close of the Persian period to have constituted a satrapy by itself (or with the mere addition of Hyrcania) in which condition it was continued by the successors of Alexander.
Tranquillity was preserved till about BC.255 when the weakness of Antiochus Theus and the success of the Bactrian rebellion, encouraged the Partians to rise against their Greek masters and to declare themselves an independent people.
Their leader in the revolt was a certain Arsaces. This person was the commander of a body of Scythian Dahae from the banks of the Ochus , who migrated into Parthia and obtaining the ascendency in the country raised their general to the position of king. There was probably, sufficient affinity between the immigrant Dahae and the previous inhabitants of the region for the two races readily to calesce; both appear to have been TURANİAN ; and the Dahae were so completely absorbed that we hear nothing of them in the subsequent history. The names of "Parthia" and "Parthian" prevailed ; and the whole nation presents to us one uniform type.
a Manual of Ancient History
from the earliest times to the fall of the western empire
Chaldaea , Assyria, Media, Babylonia, Lydia, Phoenicia, Syria, Judaea, Egypt, Carthage , Persia, Greece , Macedonia, Parthia and Rome
By GEORGE RAWLINSON , M.A. (click)
Camden Professor of ancient history ın the university of OXFORD.