SELEUCIA, in Ancient Geography, furnished Babylonia, because situated on its confines, at the confluence of the Euphrates and Tigris. Ptolemy places it in Mesopotamia. It is called also Seleucia ad Tigrim, (Polybius, Strabo, Isidorus Characenus); washed on the south by the Euphrates, on the east by the Tigris, (Theophylactus); generally agreed to have been built or enlarged by Seleucus Nicanor, master of the east after Alexander; by means of which Babylon came to be deserted. It is said to have been originally called Cochæ, (Ammian, Eutropius); though others, as Arrian, distinguish it, as a village, from Seleucia: and, according to Zosimus, the ancient name of Seleucia was Zochasia. Now called Bagdad. E. Long. 44. 21. N. Lat. 33. 10. There were many other cities of the same name, all built by Seleucus Nicanor.