As Alexander conquered new territories he introduced elements of Greek culture to his subjects as both a controlling and unifying measure. Central to this was the foundation of cities organised on Greek lines and populated with Macedonian and Greek settlers. Alexander’s successor Seleucus I Nicator (reigned 312-281 BC) continued this policy in order to maintain power over his vast empire. Each city was laid out with a Greek-style agora(market place), gymnasium and theatre. One of these cities, Seleucia-on-Tigris, became the largest and wealthiest city in Mesopotamia with an estimated population of around 60,000.

Existing Mesopotamian cities were also provided with Greek buildings. For example, a combined theatre-gymnasium was built in brick at Babylon. Temples were dedicated to Greek gods who were also represented on the reverse of Seleucid coins. Greek inscriptions on coins and elsewhere promoted the Greek language. Hellenistic art, a fusion of Greek and Near Eastern traditions emerged. This was promoted by the Seleucid kings and adopted by the local elite with the result that Hellenistic ideas and forms percolated across the empire and through society. Hellenistic culture was therefore remarkably uniform from Syria to Central Asia.