The Battle of Harran took place on 7 May 1104 between the Crusader states of the Principality of Antioch and the County of Edessa, and the Seljuk Turks. It was the first major battle against the newfound Crusader states in the aftermath of the First Crusade, marking a key turning point against Frankish expansion. The battle had a disastrous effect on the Principality of Antioch as the Turks regained territory earlier lost.