Artabanus III
The king chosen by the barons to replace Vonones was Artabanus III (reigned 12–38). They were certainly mistaken in believing they would find in him an easy instrument to manipulate. Artabanus was the son of a viceroy of Hyrcania and was Arsacid only on his mother’s side. Under his rule Parthia entered a brilliant but troubled era, one completely dominated by the personality of this violently anti-Roman sovereign who was eager to drive Rome out of Asia. However, after he failed to place his son on the throne of Armenia, for years Artabanus avoided precipitating matters with Rome and dedicated himself to internal reforms, among which centralization was the most important.
The humbling of the great nobles, an enterprise in which he was sustained by the lesser nobles, became necessary. He had to reduce the hereditary privileges the barons had carved out for themselves. It was also necessary to reorganize the states that made up the kingdom. He put princes of his family on the thrones of Mesene, Persis, Elymais, Atropatene—all little states that were governed by men loyal to the throne. But it proved impossible for him to put down a revolt in the eastern possessions, where the Indo-Parthian king Gondophares declared himself independent (c. 19) and took the title “king of kings.”
It is thought that the position taken toward the city-states, about which precise information is lacking, was the reason for the seven-year-long revolt of Seleucia on the Tigris. The fighting there took place between the Greek and Hellenized elements and the Semites, who demanded their right to participate in the autonomy of the city and who supported pretenders against Artabanus III.
A new attempt to place a son on the throne in Armenia angered Rome, which, with the aid of the nobility, sent for Tiridates III, a pretender the barons had crowned at Ctesiphon. Artabanus was forced to take refuge with the Dahae, who helped him win back his throne. In 37 a meeting with a representative of Rome on a bridge in the middle of the Euphrates allowed an agreement to be reached that maintained the status quo in Armenia and recognized Parthian sovereignty with the river as the frontier. Artabanus, a strong personality, did not seek to impose his kingdom as a world power, but he did not hesitate to make plans to regain the western provinces, the former Achaemenian possessions.