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.

The Crusades were a series of religious wars initiated, supported, and sometimes directed by the Christian Latin Church in the medieval period. The best known of these military expeditions are those to the Holy Land in the period between 1095 and 1291 that had the objective of reconquering Jerusalem and its surrounding area from Muslim rule after the region had been conquered by the Rashidun Caliphate centuries earlier. Beginning with the First Crusade, which resulted in the conquest of Jerusalem in 1099, dozens of military campaigns were organised, providing a focal point of European history for centuries. Crusading declined rapidly after the 15th century.