Parthians took part. In the troubles which broke out upon the death of
the Pseudo-Smerdis, B.C. 521, Parthia revolted, in conjunction (as it
would seem) with Hyrcania, espousing the cause of that Median pretender,
who, declaring himself a descendant of the old Median monarchs, set
himself up as a rival to Darius. Hytaspes, the father of Darius, held at
this time the Parthian satrapy. In two battles within the limits of his
province he defeated the rebels, who must have brought into the field
a considerable force, since in one of the two engagements they lost in
killed and prisoners between 10,000 and 11,000 men. After their second
defeat the Parthians made their submission, and once more acknowledged
Darius for their sovereign.

With these earliest Oriental notices of the Parthians agree entirely
such passages as contain any mention of them in the more ancient
literature of the Greeks. Hecatseus of Miletus, who was contemporary
with Darius Hystaspis, made the Parthians adjoin upon the Chorasmians in
the account which he gave of the geography of Asia. Herodotus spoke of
them as a people subject to the Persians in the reign of Darius, and
assigned them to the sixteenth satrapy, which comprised also the Arians,
the Sogdians, and the Chorasmians. He said that they took part in the
expedition of Xerxes against Greece (B.C. 480), serving in the army on
foot under the same commander as the Chorasmians, and equipped like them
with bows and arrows, and with spears of no great length. In another
passage he mentioned their being compelled to pay the Persian water tax,
and spoke of the great need which they had of water for the irrigation
of their millet and sesame crops.

It is evident that these notices agree with the Persian accounts,
both as to the locality of the Parthians and as to the fact of their
subjection to the Persian government. They further agree in assigning