A city in Upper Mesopotamia, some 35 kilometers (c. 22 mi.) south of Edessa (mod. Şanlıurfa, Turkey).
In ancient times Harran was the site of a famous moon cult, which survived well into the Islamic period. In the seventh century Harran was briefly the Umayyad capital; parts of the Great Mosque date from this period.
Though repeatedly threatened by the Franks during the first quarter of the twelfth century, Harran remained an important Muslim shield against the county of Edessa. Divisions in the Muslim world made Harran a target for the Franks in 1104; a siege mounted by Baldwin II of Edessa, Joscelin I of Courtenay, Bohemund I of Antioch, and Tancred was lifted at the approach of a relieving Muslim army. Jokürmish of Mosul and Suqmān ibn Artûq of Mardin cut the Franks of Edessa to pieces; both Baldwin and Joscelin were captured.
Harran was taken by Zangī in 1127; his governor there informed him of the weakening of Edessa’s garrison in 1144, leading to the capture of that city. Saladin used Harran, controlled by his follower Gokbori, as a base in his operations against Mosul (1182-1186). The city and citadel were strengthened by Nûr al-Dīn and by the Ayyûbids, but Har- ran was systematically depopulated and destroyed by its Mongol rulers in 1271. The Mamlûks garrisoned the citadel for a time, but the town never recovered.