When, however, Mithridates I.( Arsaces VI.), about B.C.150, had overrun the eastern provinces of Syria, and made himself master in succession of Media, Elymais, and Babylonia, the revolutionary movement excited by his successes reached Armenia, and the standard of independence was once more raised in that country.

According to the Armenian historians, an Arsacid prince, Wagharshag or Valarsaces, was established as sovereign by the influence of the Parthian monarch, but was allowed to rule independently.

A reign of twenty-two years is assigned to this prince, whose kingdom is declared to have reached from the Caucasus to Nisibis, and from the Caspian to the Mediterranean.

He was succeeded by his son, Arshag (Arsaces), who reigned thirteen years, and was, like his father, active and warlike, contending chiefly with the people of Pontus.

At his death the crown descended to his son, Ardashes, who is probably the Ortoadistus of Justin.
Such were the antecedents of Armenia when Mithridates II., having given an effectual check to the progress of the Scythians in the east, determined to direct his arms towards the west, and to attack the dominions of his relative, the third of the Armenian Arsacidse.