At an unknown date in the 20 BCs, Ariobarzanes II succeeded his relative Asinnalus as King of Media Atropatene and little is known on his reign. The ruling Armenian monarchs of the Artaxiad Dynasty, Tigranes IV with his wife who was his paternal half-sister Erato, instigated war with the aid of King Phraates V of Parthia. To avoid a full-scale war with Rome, Phraates V soon ceased his support to the Armenian ruling Monarchs. Sometime after Tigranes IV was killed in battle and Erato, had abdicated her throne. Following the murder of the previous ruling Armenian King the tyrannical Artaxias II by his courtiers; the situation surrounding Tigranes IV and Erato, the Armenians requested to the Roman emperor Augustus, a new Armenian King. Augustus found and appointed Ariobarzanes II as the new King of Armenia in 2 AD. Ariobarzanes II through his father was a distant relative of the Artaxiad Dynasty as he was a descendant of an unnamed Artaxiad Princess who was a sister of King Artavasdes II of Armenia who married Ariobarzanes II's paternal ancestorMithridates, a previous ruling King of Media Atropatene. Ariobarzanes II served as a loyal Roman Client King to Augustus and was used as a key element in Augustus’ Asian Policy. Ariobarzanes II during his Armenian Kingship also served as King of Media Atropatene. He accompanied Augustus’ grandson and adopted son Gaius Caesar to Armenia. When Gaius and Ariobarzanes II arrived in Armenia, the Armenians being fiery and proud, refused to acknowledge Ariobarzanes II as their new King, especially as he was a foreigner in their country. The Armenians revolted against Rome under the leadership of a local man named Addon. Gaius with his Roman legions ended the revolt and reduced the city of Artagira. In Artagira, Gaius made Ariobarzanes II the new King of Armenia. Ariobarzanes II made Artagira, his capital city when he ruled Armenia and Media Atropatene together. The Armenians eventually came to respect Ariobarzanes II as their ruling King, because of his noble personality, spirit and his physical beauty. In 4, Ariobarzanes II died and was succeeded his son Artavasdes in his Kingship of Media Atropatene and Armenia.
Family and issue
Ariobarzanes II from an unnamed wife had two sons:
Gaius Julius Ariobarzanes I, who may have had a son called Gaius Julius Ariobarzanes II
Inscription evidence
Ariobarzanes II is mentioned in paragraphs 27 and 33 of the Res Gestae Divi Augusti. In Rome, two Epitaph inscriptions have been found bearing the name of an Artavasdes. The Epitaphs are probably of the son and the grandson of a Median Atropatenian King called Ariobarzanes. However it is uncertain, if the Ariobarzanes refers to Ariobarzanes I or Ariobarzanes II.