Shortly after the violent death of king Phraataces in the year 6 CE, the Parthian nobility elected Orodes III as king.note[Josephus, Jewish Antiquities 18.44; Tacitus, Annals 2.2.] He was a son of Phraates IV and, therefore, Phraataces' younger brother. According to Flavius Josephus, his reign was as short as it was cruel, and in 8 CE, he was assassinated.note[Josephus, Jewish Antiquities 18.45.]
Orodes was replaced by his brother Vonones I, who had been educated in Rome as guest/hostage of the emperor Augustus.note[Tacitus, Annals 2.1.] Josephus and Tacitus both tell us that the Parthians soon regretted that they were now ruled by someone who was, as former hostage, something like a former slave.note[Josephus, Jewish Antiquities 18.47; Tacitus, Annals 2.3.]
So, a group of Parthians invited Artabanus II, also a member of the Arsacid family and (according to Josephus) "king of Media", to become king of Parthia.note[Josephus, Jewish Antiquities 18.48.] Unless this refers to Media Atropatene, an independent state in what is now Azerbaijan where Artabanus had been ruler, it is more likely that Artabanus had been living among the Dahae, a tribe on the plains of Central Eurasia, as Tacitus tells us.note[Tacitus, Annals 2.3.]
After Vonones, who still had supporters, had gained a first victory,note[Josephus, Jewish Antiquities 18.48.] he lost a second battle and retreated to Seleucia on the Tigris,note[Josephus, Jewish Antiquities 18.49.] When Artabanus proceeded to capture the Parthian capital Ctesiphon, Vonones fled to Armenia and from there returned to the Roman Empire.note[Josephus, Jewish Antiquities 18.50; Tacitus, Annals 2.4.] Augustus, perhaps acting on advice of Tiberius, refused to extradite himnote[Josephus, Jewish Antiquities 18.50.] but also refused to support him, and kept him in custody in Syria, where governor Silanus Creticus was responsible for Vonones' "toy court" (ludibrium).note[Tacitus, Annals 2.4.]
In 18 CE, the Roman prince Germanicus visited the eastern provinces of the Roman Empire and received envoys from Artabanus, who complained about Vonones' interference in the Parthian Empire. In response, Germanicus sent Vonones to Pompeiopolis in Cilicia.note[Tacitus, Annals 2.58.] When Vonones tried to escape (19 CE), he was killed by his guards.note[Tacitus, Annals 2.68.]
The chronology of the Arsacid kings of the Parthian Empire is less well-understood than, for example, the sequence of Seleucid and Ptolemaic kings or the emperors of Rome. This information is based on the researches by G.R.F. Assar, as published in "Iran under the Arsakids, 247 BC – AD 224/227" in: Numismatic Art of Persia (2011).