DIYARBAKIR, ancient AMIDA, is the second-largest city in southeastern Turkey ( the ancient "Upper Mesopotamia" ) after the Biblical city of Urfa (Edessa).
Predating Roman colonization in the 3rd Century AD, it was enlarged and strengthened under the Roman emperor Constantinus II, who also erected new walls around the city ( 349 ). After a long siege, it fell to the king of Persia in 359. It changed hands frequently in the later wars between the Romans and the Persians, and was in Byzantine hands when the Arabs took it ( c. 639 ). With the weakening of Abbasid control over the region and the emergence of the Hamdanid dynasty of Mosul ( in Iraq ) in the 10th century, Diyarbakir was ruled by various Arab, Turkish, and Persian dynasties until its capture by the Ottoman Turks in 1516.