ABSTRACT
When Demetrius II was taken prisoner by the Parthians under Mithradates II in 140/139 Bc on a campaign in the east, in a futile attempt at restoring the empire of his predecessors, this was the death knell not only for Seleucid power but for the entire system created by Cyrus the Great and Darius I, 400 years earlier. It was a sign that the political set-up of the Middle East had entered a phase of change that would result in a new constellation of political powers. When Demetrius was captured, the Parthian armies had reached the Euphrates. From now on, this was to become the border between Graeco-Roman and Iranian spheres of interest. These decades witnessed events which were to be a turning point in the history of the region, determining its development for centuries to come: the political division of the Middle East into an Iranian and a Mediterranean sphere, a division which turned out to be extremely stable. The border between these two regions remained on the whole unchanged for more than seven centuries. As will become apparent, the division had far-reaching consequences for politics and culture, not only in Syria and Mesopotamia, the countries immediately affected, but for the whole area stretching from South Arabia to the Caspian Sea.
