The Mamluks defeat the Mongols at the Battle of Ain Jalut in Palestine, marking their first decisive defeat and the point of maximum expansion of the Mongol Empire.

The Battle of Ain Jalut (Arabic: , romanized: Ma'rakat Ayn Jlt), also spelled Ayn Jalut, was fought between the Bahri Mamluks of Egypt and the Mongol Empire on 3 September 1260 (25 Ramadan 658 AH) in southeastern Galilee in the Jezreel Valley near what is known today as the Spring of Harod (Arabic: , romanized: Ayn Jlt, lit.'Spring of Goliath'). The battle marked the height of the extent of Mongol conquests, and was the first time a Mongol advance was permanently beaten back in direct combat on the battlefield.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 sent envoys to Cairo demanding Qutuz surrender Egypt, to which Qutuz responded by killing the envoys and displaying their heads on the Bab Zuweila gate of Cairo. Shortly after this, Hulagu returned to Mongolia with the bulk of his army in accordance with Mongol customs, leaving approximately 10,000 troops west of the Euphrates under the command of general Kitbuqa.

Learning of these developments, Qutuz quickly advanced his army from Cairo towards Palestine. Kitbuqa sacked Sidon, before turning his army south towards the Spring of Harod to meet Qutuz' forces. Using hit-and-run tactics and a feigned retreat by Mamluk general Baibars, combined with a final flanking maneuver by Qutuz, the Mongol army was pushed in a retreat toward Bisan, after which the Mamluks led a final counterattack, which resulted in the death of several Mongol troops, along with Kitbuqa himself.

The battle has been cited as the first time the Mongols were permanently prevented from expanding their influence, and also incorrectly cited as the first major Mongol defeat. It also marked the first of two defeats the Mongols would face in their attempts to invade Egypt and the Levant, the other being the Battle of Marj al-Saffar in 1303. The earliest known use of the hand cannon in any military conflict is also documented to have taken place in this battle by the Mamluks, who used it to frighten the Mongol armies, according to Arabic military treatises of the 13th and 14th centuries.

Mamluk (Arabic: مملوك, romanized: mamlūk (singular), مماليك, mamālīk (plural), translated as "one who is owned", meaning "slave", also transliterated as Mameluke, mamluq, mamluke, mameluk, mameluke, mamaluke, or marmeluke) is a term most commonly referring to non-Arab, ethnically diverse (mostly Turkic, Caucasian, Eastern and Southeastern European) slave-soldiers and freed slaves to which were assigned military and administrative duties, serving the ruling Arab dynasties in the Muslim world.The most enduring Mamluk realm was the knightly military class in Egypt in the Middle Ages, which developed from the ranks of slave-soldiers. Originally the Mamluks were slaves of Turkic origin from the Eurasian Steppe, but the institution of military slavery spread to include Circassians, Abkhazians, Georgians, Armenians, and Russians, as well as peoples from the Balkans such as Albanians, Greeks, and South Slavs (see Saqaliba). They also recruited from the Egyptians. The "Mamluk/Ghulam Phenomenon", as David Ayalon dubbed the creation of the specific warrior class, was of great political importance; for one thing, it endured for nearly 1,000 years, from the 9th to the 19th centuries.

Over time, Mamluks became a powerful military knightly class in various Muslim societies that were controlled by Arab rulers. Particularly in Egypt, but also in the Levant, Mesopotamia, and India, mamluks held political and military power. In some cases, they attained the rank of sultan, while in others they held regional power as emirs or beys. Most notably, Mamluk factions seized the sultanate centered on Egypt and Syria, and controlled it as the Mamluk Sultanate (1250–1517). The Mamluk Sultanate famously defeated the Ilkhanate at the Battle of Ain Jalut. They had earlier fought the western European Christian Crusaders in 1154–1169 and 1213–1221, effectively driving them out of Egypt and the Levant. In 1302 the Mamluk Sultanate formally expelled the last Crusaders from the Levant, ending the era of the Crusades.While Mamluks were purchased as property, their status was above ordinary slaves, who were not allowed to carry weapons or perform certain tasks. In places such as Egypt, from the Ayyubid dynasty to the time of Muhammad Ali of Egypt, mamluks were considered to be "true lords" and "true warriors", with social status above the general population in Egypt and the Levant. In a sense, they were like enslaved mercenaries.