Mesopotamia has, since the second century BC, been a part of the Parthian empire.http://www.timemaps.com/history/middle-east-30bc Chronic political instability, together with the continuous wars with external foes (Seleucids, Steppe Nomads and, latterly, Romans)http://www.timemaps.com/history/europe-30bc have prevented the Parthian kings from properly consolidating their control over Mesopotamia. As a result, several semi-independent kingdoms, only loosely subordinate to the Parthian monarchs, now cover large parts of the region, for example Characene, Adiabene and Gordyene.
Most of the Parthian kings have been anxious to present themselves as pro-Greek in their sympathies. They have followed a policy of promoting “Hellenistic” civilization within the cities, and Greek continues as the international language of trade and urban culture within the empire. Aramaic is spoken by most of the rural population.
The pro-Greek policies, however, are far from being universally popular amongst the Parthian ruling class. They are therefore vulnerable to changes in political fortunes, and the anti-Greek sentiments of the traditional Parthian nobility are gaining in strength.
ORIGINAL SOURCE: timemaps.com