In B.C. 250 a certain Arsaces, who seems by his coins to have been the chief of a band of Dahæ Scythians dwelling near the Oxus, overthrew Andragoras, nominally satrap of Parthia, and set himself up as king of Parthia.[21] He was the founder of the famous dynasty of the Arsacidæ. As Mr. Gardner[22] observes, the “so-called history of Parthia is really the history of Central Asia under the Arsacidæ.”
After a reign of two years he was killed in battle, leaving his kingdom to his brother Tiridates, who was the real founder of the Parthian power. The fifth king of this dynasty was Mithridates (B.C. 190), who extended his conquests to such a degree that, according to Justin, his sway included the Himalayas and the Euphrates.[23] He also compelled Eucratides, the powerful king of Bactria, who had come to the throne about B.C. 170, to cede certain districts of his kingdom.
After a glorious reign he died about B.C. 140, and was succeeded by his brother Phraates.[24] The Syrian Empire of the Seleucidæ was fast falling to pieces, and Parthia was never again invaded by the Greeks. But a more terrible foe was approaching from the East,[25] for it now came into collision with a Scythian band, called “Su” or “Se” in the Chinese annals, which in the second century B.C. had overrun the provinces bordering the Jaxartes. They are identical with the Sacæ of classical writers, and were afterwards known in Upper India as the Sakas. Phraates[26] summoned a band of these savages to aid him against the Syrian Antiochus. Arriving at the scene of action too late to be of service in the campaign, they turned against him, defeated his army and slew him.
He was succeeded by his nephew Artabanus II., who after a brief reign fell in battle against the Thogari,[27] mentioned by Strabo as one of the four great Saka tribes.[28] His son Mithridates II., justly distinguished by the appellation “Great,” revived the fading glories of the Parthian Empire. He commenced his reign by administering several crushing defeats to the Sakas, from whom he wrested the greater portion of Bactria. But he was destined to meet a foe more worthy of his steel, and finally to submit after a lifelong struggle. The Romans had entered on the career of foreign conquest which seems inevitable in the case of a powerful republic. Greece was theirs, and they had planted their eagles in Asia Minor.