SELEUCIA, (anc. geogr.) furnished Babylonia, because situate 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 Nicator, 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 Zebasia. Now called Bagdad. E. Long. 44. 21. N. Lat. 33. 10. There were many other cities of the same name, all built by Seleucus Nicator.