From the late seventh century the Byzantine state used compulsory population transfer as a standing instrument of policy. Justinian II moved Slavic groups from Macedonia into Bithynia in Asia Minor, forming from them a military corps that Theophanes numbers at 30,000; when much of it defected to the Arabs in 692 the emperor is said to have had the settlers' families killed. Constantine V moved Armenians and Syrians from the eastern frontier into depopulated Thrace in the 750s and moved others in the reverse direction, using transfer at once to repopulate, to garrison and to dilute communities regarded as religiously or politically suspect. Peter Charanis's 1961 study established transfer as a continuous policy rather than a set of emergencies. The figures are almost entirely absent, and where present are round chronicle numbers; the practice is nonetheless securely documented across two centuries.
Byzantine emperors — notably Justinian II, Constantine V and their successors — moved whole populations across the empire to garrison frontiers, repopulate devastated provinces and break up communities judged unreliable
Warren Treadgold's reconstruction from army pay, fiscal and thematic records puts the empire at roughly 7 million around 780, down from perhaps 19 million in the sixth century before plague and territorial loss. No register of the transferred populations survives; the individual transfers are known only from chronicle notices that give round numbers or none.
No usable figures. Transfer was intended to move populations rather than destroy them; the one killing reported in this context, the massacre of the deserters' families in 692, is given without numbers by Theophanes and is not corroborated.
Turkey, Macedonia, Bulgaria