Continuing the westward expansion of the Mongol Empire, the armies of Hulagu Khan captured and sacked Baghdad in 1258, along with the Ayyubid capital of Damascus sometime later.
Hulagu returned to Mongolia with the bulk of his army to attend the kurultai in accordance with Mongol customs, leaving approximately 10,000 troops west of the Euphrates under the command of Kitbuqa.
[10] 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),[2] and a handful of vassal troops under the Naiman Nestorian Christian general Kitbuqa.
[14] Contemporary Mamluk chronicler al-Yunini's Dhayl Mirat Al-Zaman states that the Mongol army under Kitbuqa, including vassals, numbered 100,000 men in total, but this was likely an exaggeration.
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.
[16] Upon receiving news of Hulagu's departure, Mamluk Sultan Qutuz quickly assembled a large army at Cairo and invaded Palestine.
[11] In late August, Kitbuqa's forces proceeded south from their base at Baalbek, passing to the east of Lake Tiberias into Lower Galilee.
[12] The Mongols attempted to form a Franco-Mongol alliance or at least to demand the submission of the remnant of the Crusader Kingdom of Jerusalem, now centered on Acre; but Pope Alexander IV had forbidden it.
[12] Though the Mamluks were the traditional enemies of the Franks, the Barons of Acre recognised the Mongols as the more immediate menace and so the Crusaders opted for a position of cautious neutrality between the two forces.
When Qutuz saw the left wing of the Mamluk army almost destroyed by the desperate Mongols seeking an escape route, he threw away his combat helmet, so that his warriors could recognize him and cried loudly three times "O Islam!
The Mongols were pushed back and fled to a vicinity of Beisan, followed by Qutuz's forces, but they managed to reorganize and to return to the battlefield, making a successful counterattack.
Hulagu Khan ordered the execution of the last Ayyubid emir of Aleppo and Damascus, An-Nasir Yusuf, and his brother, who were in captivity, after he heard the news of the defeat of the Mongol army at Ain Jalut.
Internecine conflict prevented Hulagu Khan from being able to bring his full power against the Mamluks to avenge the pivotal defeat at Ain Jalut.
[23] After the Mongol succession was finally settled, with Kublai as the last Great Khan, Hulagu returned to his lands by 1262 and massed his armies to attack the Mamluks and avenge Ain Jalut.
[26][27] Hassan's claims are contradicted by other historians such as David Ayalon, Iqtidar Alam Khan, Joseph Needham, Tonio Andrade, and Gabor Ágoston.
[30] However the term midfa, dated to textual sources from 1342 to 1352, cannot be proven to be true hand-guns or bombards, and contemporary accounts of a metal-barrel cannon in the Islamic world do not occur until 1365.
[34][35] A recent study claims that the Mongol defeat was in part caused by a short term climate anomaly following the eruption of Samalas volcano a few years earlier, stating that "a return to warmer and dryer conditions in the summer of 1260 CE, [...] likely reduced the regional carrying capacity and may therefore have forced a mass withdrawal of the Mongols from the region that contributed to the Mamluks’ victory.
[37] In July 1970, Yasser Arafat referred to the modern area in the context of the historical battle:[38] This will not be the first time that our people has vanquished its enemies.