Ancient city, on the Tigris River , central Iraq.
Founded by Seleucus I Nicator in the late 4th century BC as his eastern capital, it replaced Babylon as Mesopotamia 's leading city. The population, which Pliny the Elder estimated at 600,000, was composed largely of Macedonians and Greeks and also included Jews and Syrians. During the Parthian domination of the Tigris-Euphrates valley that began in the 2nd century BC, it maintained its position and trade despite its Greek sympathies. In AD 165 the Romans burned the city, marking the end of Hellenism in Mesopotamia. See also Seleucid dynasty .