King Tigranes IV (r.c.8 BCE - 2 CE) had been the last one to effectively rule Armenia, but the Roman emperor Augustus had objected Tigranes' pro-Parthian policy and had tried destabilize his reign, first by sending a rival king, Artavasdes,note[Cassius Dio, Roman History 55.10.20.] and later, after Tigranes IV had "perished in a war with barbarians"note[Cassius Dio, Roman History 55.10a.5.] by appointing Ariobarzanes, who was not an Armenian and had an accident. He was replaced by his son Artavasdes III, who was almost immediately assassinated.note[Augustus, Res Gestae 27.]
The Roman historian Tacitus continues that
after an experiment in female government with a queen called Erato, who was quickly expelled, the drifting, disintegrated people, ownerless rather than emancipated, welcomed the fugitive Vonones to the throne.note[Tacitus, Annals 2.4.]
Tacitus forgets to mention Erato's husband Tigranes V, who became king in the year 6 CE. Six rulers in about four years: we may forgive Tacitus for believing that the Armenian monarchy had disintegrated. However, he ignores the reign of Zeno, a son of Polemon I Eusebes of Pontus and queen Pythodoris. Zeno was placed on the Armenian throne by the Roman prince Germanicus in the year 18, accepted the throne name of Artaxias, and was king until 34.