I. History – II. Archaeology. I. History. Founded in 304 BC by Seleucus I, Edessa enters history only in 132 BC, when the Seleucids, retreating westward over the Euphrates, abandoned Mesopotamia to the Parthians. It was then that the kingdom of Osroene was established, with Edessa as capital. The representatives of the dynasties that succeeded each other in this kingdom over some 375 years 132 BC AD 244 were mostly Nabatean Arabs or Parthians. The region’s population, however, was of varied origin: mixed with native Arameans were Nabatean Arabs, Parthians, descendents of Macedonian colonists, Persians and Jews. This ethnic diversity ensured the coexistence of different religious currents in the paganism of Edessa: alongside Babylonian divinities like Nabu and Baal were venerated the goddess Atargatis and the god Hadas of Harran, and all the gods of the pantheon of the desert Arabs. Castration in honor of Atargatis, goddess of fertility, was widely practiced; Chaldaean astrology was much in vogue. Moreover, Edessa’s medicinal springs gave it the prestige of a center of miraculous cures. Origins of Christianity. The Syriac work known as Doctrina Addai attributes the evangelization of Edessa to Addai or Addaeus, a disciple sent by Jesus himself: Addai converts and baptizes King Abgar V Uchama the Black. Eusebius of Caesarea relates this episode and mentions an exchange of letters between Jesus and Abgar, to which he attributes historical value HE I, 13; II, 1,6-7. This text, likely legendary, goes back to the late 4th or early 5th c. and reflects the viewpoint of orthodox Christianity at the time of Ephrem the Syrian d. 373. The Armenian church took up this legend in order to derive its origin from the apostles. What is certain is that Edessa, given its position on the silk route, was evangelized very early. Syrian Christianity recruited its first followers among the Jewish communities of Adiabene, numerous at that time in that kingdom, whose dynasty had, since its rulers’ conversion to Judaism, long maintained close relations with Palestine. So Christianity seems to have begun its spread into Osroene from the east, rather than from Palestine. This hypothesis is strengthened by the fact that the Syriac version of the OT, known as Peshitta the Simple, seems to have originated among the Jews of Edessa.