EDESSA: An important city of Northern Mesopotamia. It is located on the Daisan, an eastern tributary of the Euphrates, nearly midway between Diarbekir and Aleppo on the straight line which joins them, in 37° 21' n. lat., and 39° 6' e. long. The Targum of pseudo-Jonathan, Jerome, and Ephraem Syrus wrongly identified the city with the Erech of Gen. x. 10, and this may be reflected in the Arabic tradition which connects the place with the death of Abraham, after whom the principal mosque of the city is called. The early name is unknown. The city came into historical prominence as a part of the Greek empire in the time of Seleucus, who possibly renamed it after the Macedonian Edessa, though an etymological suggestion is that Edessa is a corruption of the Syriac Haditha, "New City." By the Greeks it was also called Callirrhoe (doubtless from its fountain), whence came the Syrian name Urhoi, the Arabic el-Roha, and the Turkish Urfa.
Edessa remained theoretically a city of the Seleucid kingdom till 136 B.C., when it became the capital of the Osrohenic (Chosroenic) kingdom founded by Osrhoes (Orhoi bar-Khevyo), among whose successors was Abgar (q.v.), famous for the alleged correspondence with our Lord (Eusebius, Hist. eccl., I., xxiii. sqq.). It was plundered by Trajan's general Lucius Quietus, 116 A.D., and the kingdom was made tributary to the Romans, though its independence was restored by Hadrian, probably the following year. In 217 its autonomy was ended by Caracalla, and a Roman colony was established there. During the next century it suffered severely in the wars between Romans and Persians, and it was visited by Julian, who proposed to distribute the wealth of the native Christians and churches among his soldiers. In 609 the Persians were in possession, and in 641 the Mohammedans took it. It was captured in the crusade under Godfrey of Bouillon in 1097 and remained in Christian hands till 1144, when it again became a Moslem possession. In 1234 it belonged to the Byzantines, Tamerlane took it in 1393, and the Turks in 1637.
The city was early a seat of Christianity, and an untrustworthy tradition attributes the introduction of the religion to Thaddeus (see JUDAS) or to Addai, alleged to be one of the Seventy sent by Thomas the Apostle (see ABGAR, and cf. Acta Thaddæi, APOCRYPHA, B, II., 12). This Syrian tradition makes Addai the first bishop, and his immediate successors Aggæus and Barsimæus. The first Christian church built there is said to have been destroyed by a flood in 202 A.D., which testifies to the early establishment of Christianity there. In the third century it was the seat of a bishop, and in the fourth was a city of monasteries as well-as the chief seat of Syrian Christian learning with its famous schools whence issued a long line of famous scholars. Ephraem Syrus made it his home, and Sozomen (Hist. eccl., vi. 18) affirms that in the time of Valens (363-378) most of the inhabitants were Christians. The type of Christianity seems to have changed from orthodox to Arian and later to Nestorian. Under Diocletian it appears to have been the scene of many martyrdoms, and under Sapor II. of Persia the Christians there suffered severe persecutions. It is still the seat of an Armenian archbishop, and it gives the name to a titular Roman Catholic archbishopric. Its present population is estimated at between 30,000 and 50,000, nearly all Mohammedans, with about 2,000 Armenian Christians and about 500 Jews.
GEO. W. GILMORE.
Bibliography: The basal source for the early history is the Chronicon Edessenum, ed. I. Guidi, in Syriac and Latin, 1903, also in J. S. Asseman, Bibliotheca orientalis, i. 388417, Rome, 1719; consult also T. L. Bayer, Hist. Osrhoena et Edessena ex nummis illustrata, St. Petersburg, 1734. The Christian sources are indicated in the text in the ecclesiastical histories of Eusebius, I. xiii. sqq., Sozomen, iii. 14, 16, and Socrates, iv. 18. Consult further: L. J. Tixeront, Les Origins de l'église d'Édesse, Paris, 1888; A. Buff a, La Légende d'Abgar et lea origins de l'église d'Édesse, Geneva, 1893; F. C. Burkitt, Early Eastern Christianity, chap. i, London, 1904.