actrian kingdoms cannot but have trembled for their newly won
independence. Here was a young warrior who, in a single campaign, had
marched the distance of a thousand miles, from the banks of the Nile to
those of the Lower Euphrates, without so much as receiving a check, and
who was threatening to repeat the career of Alexander. What resistance
could the little Parthian state hope to offer to such an enemy? It
must have rejoiced Tiridates to hear that while the new conqueror was
gathering somewhat too hastily the fruits of victory, collecting and
despatching to Egypt the most valuable works of art that he could find
in the cities which he had taken, and levying heavy contributions on the
submitted countries, a revolt had broken out in his own land, to quell
which he was compelled to retire suddenly and to relinquish the greater
part of his acquisitions. Thus the threatened conquest proved a mere
inroad, and instead of a power of greater strength replacing Syria in
these regions, Syria practically retained her hold of them, but with
enfeebled grasp, her strength crippled, her prestige lost, and her honor
tarnished. Ptolemy had, it is probable, not retired very long, when,
encouraged by what he had seen of Syria's weakness, Tiridates took the
aggressive, and invading the neighboring district of Hyrcania, succeeded
in detaching it from the Syrian state, and adding it to his own
territory. This was throwing out a challenge which the Syrian monarch,
Callinicus, could scarcely decline to meet, unless he was prepared to
lose, one by one, all the outlying provinces of his empire.

Accordingly in B.C. 237, having patched up a peace with his brother,
Antiochus Hierax, the Syrian monarch made an expedition against Parthia.
Not feeling, however, altogether confident of success if he trusted
wholly to his own unaided efforts, he prudently entered into an alliance
with Diodotus the Bactrian king, and the two agreed to combine their
forces against Tiridates. Hereupon that monarch, impressed with a
deep sense of the impending danger, quitted Parthia, and, proceeding
northwards, took refuge with the Aspasiacae, a Scythian tribe which
dwelt between the Oxus and the Jaxartes. The Aspasiacae probably lent
him troops; at any rate, he did not remain long in retirement, but,
hearing that the Bactrian king, whom he especially feared, was dead, he
contrived to detach his son and successor from the Syrian alliance, and
to draw him over to his own