Hulagu withdrew from the Levant with the bulk of his army, leaving his forces west of the Euphrates with only one tumen (nominally 10,000 men, but usually fewer) under the Naiman Nestorian Christian general Kitbuqa Noyan.
Until the late 20th century, historians believed that Hulagu's sudden retreat had been caused by the power dynamic having been changed by the death of the Great Khan Möngke on an expedition to the Song dynasty's China, which made Hulagu and other senior Mongols return home to decide his successor. However, contemporary documentation discovered in the 1980s reveals that to be untrue, as Hulagu himself claimed that he withdrew most of his forces because he could not sustain such a large army logistically, that the fodder in the region had been mostly used up and that a Mongol custom was to withdraw to cooler lands for the summer.
Upon receiving news of Hulagu's departure, Mamluk Sultan Qutuz quickly assembled a large army at Cairo and invaded Palestine. In late August, Kitbuqa's forces proceeded south from their base at Baalbek, passing to the east of Lake Tiberias into Lower Galilee. Qutuz was then allied with a fellow Mamluk, Baibars, who chose to ally himself with Qutuz in the face of a greater enemy after the Mongols had captured Damascus and most of Bilad ash-Sham.