Phraates I
[4] New epigraphic evidence from Nisa suggests that Priapatius following his death in 170 BC may have been succeeded by an obscure figure named Arsaces IV, who briefly ruled for two years.[8] At the start of 165 BC, Phraates attacked the powerful Mardians (also known as Amardians), a group of people who lived in Alborz mountains, which bordered Hyrcania in the east and Media in the southwest.[9] Phraates' attack on the Mardians was successful, conquering the Caspian Gates, as well as the city of Charax, which was close to the Median metropolis of Rhaga.His successor, the nine-year-old Antiochus V Eupator (r. 164 – 161 BC) was unable to focus on the Parthians, as his reign was marked by conflict, political intrigue, and Roman influence.[12] Justin reports that the interests of the country was of higher importance to Phraates I than that of his sons, which indicates that he supported the decision made by his father regarding the succession.