The Artaxiad or Ardaxiad dynasty (Artashesian dynasty,) ruled the kingdom of Armenia from 189 BC until their overthrow by the Romans in AD 12. Their realm included Greater Armenia, Sophene and intermittently Lesser Armenia and parts of Mesopotamia. Their main enemies were the Romans, the Seleucids and the Parthians, against whom the Armenians conducted multiple wars. According to the geographer Strabo, Artaxias and Zariadres were two satraps of the Seleucid Empire, who ruled over the provinces of Greater Armenia and Sophene respectively. After the Seleucid defeat at the Battle of Magnesia in 190 BC, a coup by the Armenian noble family of Artashes toppled the Yervanduni dynasty and declared their independence, with Artaxias becoming the first king of the Artaxiad dynasty of Armenia in 188 BC. Scholars believe that Artaxias and Zariadres were not foreign generals but local figures related to the previous Orontid dynasty, as their Irano-Armenian (and not Greek) names would indicate. According to Nina Garsoïan / Encyclopaedia Iranica, the Artaxiads were a branch of the earlier Orontid (Eruandid) dynasty of Iranian origin attested as ruling in Armenia from at least the 5th century BC. Artaxias is regarded as one of the most important kings in Armenian history. He presented himself as a legitimate descendant of Orontids, although it is unknown if he was in fact related to that dynasty. In the beginning of his rule, parts of the Armenian Highlands with Armenian speaking populations remained under the rule of neighbouring states. Artaxias made the reunification of those lands under his domain a priority. Greek geographer and historian Strabo recounts the conquests of Artaxias towards West, East, North and South. Strabo, Geography, book 11, chapter 14: "According to report, Armenia, though a small country in earlier times, was enlarged by Artaxias and Zariadris, who formerly were generals of Antiochus the Great, but later, after his defeat, reigned as kings (the former as king of Sophene, Acisene, Odomantis, and certain other countries, and the latter as king of the country round Artaxata), and jointly enlarged their kingdoms by cutting off for themselves parts of the surrounding nations,--I mean by cutting off Caspiane and Phaunitis and Basoropeda from the country of the Medes; and the country along the side of Mt.