Duluk (mod. Dülük, Turkey) was a small town in northern Syria, the seat of a Latin archbishopric during the existence of the county of Edessa.
Dolichè or Tulupe, as it was known in ancient times, had once been of regional importance but had been superseded by Aintab (mod. Gaziantep, Turkey) and, during the Frankish period, by Turbessel (mod. Tellbaflar Kalesi, Turkey), which were more accessible and better-watered sites. At the foot of the mountains, near the route north to Marash (mod. Kahramanmaraş, Turkey), Duluk was in the territory controlled by the Armenian lord Kogh Vasil at the time of the First Crusade (1096-1099). It was in Frankish hands after 1116, although possibly earlier; Count Baldwin II of Edessa was briefly besieged there by Tancred in 1108. One Mahuis, count of Duluk, was at the battle of Azaz (1125); a Latin archbishop, Franco, is attested in 1134 and 1141 but was resident at Turbessel.
After the capture of Count Joscelin II of Edessa (1150), Duluk was sold by his wife, Beatrix, to the Byzantine emperor. However, it was seized in the summer of 1151 by Mas‘ûd I, Saljûq sultan ofRûm, and in 1155 by Nûr al-Din.