throne and appoint his own son instead. This attempt was instantly opposed by the Romans, who regarded this as posing a danger to their interests. As a result, the Roman emperor Tiberius ( AD) sent his stepson Germanicus to prevent this from happening. However, the Roman general met no resistance from the Parthians. Instead, Germanicus reached an agreement with Artabanus to appoint Artaxias III the new king of Armenia and renounce their support of Vonones I. The Romans thus acknowledged Artabanus as the legitimate Parthian ruler. In order to ratify the friendly relationship between the two empires, Artabanus and Germanicus met on an island in the Euphrates in 18 AD. The Romans moved Vonones I to Cilicia, where he was killed the following year after attempting to flee. His death and the now unchallenged dominance of Artabanus split the Parthian nobility, since not all of them supported a new branch of the Arsacid family taking over the empire. In 19/20 AD, the Parthian satrap of Sakastan, Drangiana and Arachosia, named Gondophares, declared independence from Artabanus and founded the Indo-Parthian Kingdom. He assumed the titles of "Great King of Kings" and "Autokrator", demonstrating his new-found independence. Nevertheless, Artabanus and Gondophares most likely reached an agreement that the Indo-Parthians would not intervene in the affairs of the Arsacids. Artabanus spent the following years increasing his authority. To the north-east, he was victorious in his efforts to have a new dynasty established in Khwarazm, thus starting a new era in the history of the country. Artabanus most likely operated in western Bactria as well, which had been part of the Parthian domains for centuries. In 35 AD, Artabanus tried again to conquer Armenia and to establish his son Arsaces I as Armenia's king. A war with Rome seemed inevitable. The faction among the Parthian magnates which was hostile to Artabanus II applied to Tiberius for a king who was a descendant of Phraates IV. Tiberius sent Phraates IV's grandson, Tiridates III, and ordered Lucius Vitellius the Elder (the father of the Roman emperor Vitellius) to restore Roman authority in the East. By very dexterous military and diplomatic operations Vitellius succeeded completely. Artabanus II was deserted by his followers and fled to the East. Tiridates III, who was proclaimed King, could not keep control of the Parthian throne, because he appeared to his subjects to be a vassal of the Romans. In the meantime,