The period of greatest Armenian expansion occurred with Tigranes II (The Great; 95–55 BC) who made it the most powerful state east of Rome, as the various kingdoms of western Anatolia were absorbed into the Roman sphere of influence. He consolidated his influence within Armenia, once again taking over Sophene after deposing Artanes he king. This was the period of the Mithridatic Wars (88–63 BC) between Pontus, his north western neighbour, and Rome. He formed an alliance with Mithridates VI of Pontus (120–63 BC), marrying his daughter Cleopatra. By acquiring Syria, Phoenicia and Cilicia he effectively reduced the Seleucid empire to a rump state. The aggressive behaviour of both Pontus and Armenia inevitably and fatally brought them into conflict with the eastward Roman expansion with the Armenians suffering a decisive defeat at the Battle of Tigranocerta (69 BC). By 67 BC Pompey had arrived in eastern Anatolia with the express purpose of crushing these two states. Tigranes surrendered in 66 BC, and Armenia became a client state. The remaining members of the dynasty, which eventually petered out in 1 BC, had an uneasy relationship with both Rome to the west and Parthia to the east from which. Rome saw Armenia as a buffer state in relation to Parthia, requiring frequent interventions by the Romans.