a town of Asiatic Turkey, capital of a pashalic of the same name, on the left bank of the Euphrates, 92 miles S.E. of Birr. It contains the ruins of a palace of the Caliph Haroun-al-Raschid. The ancient Nisibis, a town founded by the Macedonians, occupied this site; a fortress was erected by Justinian; and new defences were added by the Emperor Leo, from whom it got the name of Leontopolis. Pop. 8000.