Their strongest hold was on Syria, and in the end their only hold. We associate them in our minds particularly with the great city of Antioch, which the first Seleucus founded on the Lower Orontes to gather up trade from Egypt, Mesopotamia and Asia Minor in the North Syrian country. But, as a matter of fact, that city owes its fame mainly to subsequent Roman masters. For it did not become the capital of Seleucid preference till the second century B.C.--till, by the year 180, the dynasty, which had lost both the Western and the Eastern provinces, had to content itself with Syria and Mesopotamia alone. Not only had the Parthians then come down from Turkestan to the south of the Caspian (their kings assumed Iranian names but were they not, like the present rulers of Persia, really Turks?), but Media too had asserted independence and Persia was fallen away to the rule of native princes in Fars. Seleucia on Tigris had become virtually a frontier city facing an Iranian and Parthian peril which the imperial incapacity of the Seleucids allowed to develop, and even Rome would never dispel. On the other flank of the empire a century of Seleucid efforts to plant headquarters in Western Asia Minor, whether at Ephesus or Sardes, and thence to prosecute ulterior designs on Macedonia and Greece, had been settled in favour of Pergamum by the arms and mandate of the coming arbiter of the East, the Republic of Rome. Bidden retire south of Taurus after the battle of Magnesia in 190, summarily ordered out of Egypt twenty years later, when Antiochus Epiphanes was hoping to compensate the loss of west and east with gain of the south, the Seleucids had no choice of a capital. It must thenceforth be Antioch or nothing.
That, however, a Macedonian dynasty was forced to concentrate in north Syria whatever Hellenism it had (though after Antiochus Epiphanes its Hellenism steadily grew less) during the last two centuries before the Christian era was to have a momentous effect on the history of the world. For it was one of the two determining causes of an increase in the influence of Hellenism upon the Western Semites, which issued ultimately in the Christian religion. From Cilicia on the north to Phoenicia and Palestine in the south, such higher culture, such philosophical study as there were came more and more under the influence of Greek ideas, particularly those of the Stoic School, whose founder and chief teacher (it should never be forgotten) had been a Semite, born some three hundred years before Jesus of Nazareth. The Hellenized University of Tarsus, which educated Saul, and the Hellenistic party in Palestine, whose desire to make Jerusalem a southern Antioch brought on the Maccabaean struggle, both owed in a measure their being and their continued vitality to the existence and larger growth of Antioch on the Orontes.