The Hellenistic kingdoms that succeeded Alexander built their power on new cities, and populating those cities frequently meant moving people who had no choice in the matter. Seleucus I's foundation of Seleucia-on-the-Tigris drew off much of the population of Babylon, and Antioch, Apamea, Laodicea and dozens of other foundations absorbed existing villages and towns by synoecism, the compulsory merging of communities into a single new civic centre. Settler groups were also transplanted deliberately across the empire for security reasons: Josephus preserves a letter of Antiochus III instructing his viceroy Zeuxis to move 2,000 Jewish families from Mesopotamia and Babylonia to garrison points in Lydia and Phrygia, granting them land, their own laws and a decade's tax relief in return for holding disturbed territory. The policy reshaped the demography of the Near East and created the Greek-speaking urban networks of the region, but it was executed by royal command and the numbers involved are almost never recorded.
Alexander's successors, above all the Seleucid kings, founded and repopulated cities across the Near East by compulsory synoecism of existing communities and by transplanting settler groups from one part of the empire to another
No defensible denominator exists. The Seleucid realm at its height stretched from the Aegean to the Iranian plateau and was never enumerated; modern estimates of its population differ by more than a factor of two, from roughly 14 million to 25 million or more in the reconstructions of Aperghis and others, and the compulsory synoecisms that founded cities such as Antioch and Seleucia acted on individual localities whose sizes are unrecorded.
There was no significant death toll attached to the transplantation policy itself. These were state-organised transfers of populations intended to be productive at their destination, and the sources record grants of land and tax relief rather than killing.
Turkey, Iraq