Vonones I of Parthia, having been educated as a Roman, is despised by the Parthian nobility as a slave of the Romans.

Artabanus II, who is living among the Dahan nomads in the east of Parthia (and who seems to have been a non-Arsacid Parthian nobleman), is invited to the throne between CE 8 and 10 by those Parthian grandees who will not acknowledge Vonones I, who proves to have too tight a control over the budget.

However, when Artabanus attempts to consolidate his position (at which he is successful in most instances), he fails to do so in the regions where the Parthian provincial rulers hold sway.

The war between the two pretenders is long and doubtful; on a coin Vonones mentions a victory over Artabanus.

The coins of Vonones I date from 8 to 12 CE and bear the inscription "King Vonones, conqueror of Artabanus", commemorating a temporary victory over his rival.

Those of Artabanus II begin in the year 10.

At last Artabanus defeats his rival completely and occupies the Parthian capital, Ctesiphon.