Starting in the 1240s, the Mongols attempted repeated invasions of Syria. Most failed, but they did have some success in 1260 and 1300, capturing Aleppo and Damascus and destroying the Ayyubid dynasty. The Mongols were forced to retreat within months each time by other forces in the area, primarily the Egyptian Mamluks. The post-1260 conflict has been described as the Mamluk–Ilkhanid War.
Background The Mongol expansion was guided by the idea that the “eternal sky” had destined the Great Khan to rule over the entire world. In 1219, Genghis Khan launched a large-scale offensive against the Anushtegin dynasty, which ruled most of the eastern Islamic world. By 1223, the Anushteginids had been defeated and their territory incorporated into the Mongol Empire. The main objectives of the limited Mongol government of the newly acquired region were to quell rebellions and collect as much tax and tribute as possible. Despite its relatively limited size, the Mongol army gradually expanded its sphere of influence and eventually reached Anatolia. However, some regions remained untouched by the Mongols, including the southern Iranian dynasties and the strongholds of the Ismacīlī. Furthermore, despite numerous Mongol raids, the Jazīra and the Caliphate's empire in Iraq had not yet been subjugated.
International relations In the second half of the 13th century, civil war had erupted in the Mongol Empire. In the Middle East, this manifested as conflict between the Mongols of the Golden Horde, and the Mongols of the Ilkhanate, who battled over claims on Georgia and Azerbaijan. Both the Golden Horde and the Ilkhanate sought to strengthen their position via trade agreements or other types of alliances with other powers in the area. In 1261, Berke of the Golden Horde allied with the Mamluk Sultan Baibars,Ryley-Smith in Atlas of the Crusades, p.112 (French Edition): "When the Golden Horde allied with the Mamluks, the Ilkhanate looked towards an alliance with the Christians""The alliance which Berke had created between the Mongols and the Mamluks against the Ilkhanate remained constant", Morgan, p.144"The Mongols of Iran were all but encircled by a chain of alliances linking the Mamluks to the Golden Horde, and this power to Kaidu", Setton, p.529"The friendship between Egypt and the Golden Horde, which would last until the conclusion of peace between the Mamluks and the Il-Khan in 1320" The New Cambridge Medieval History, page 710, by David Abulafia - 1999"In order to fight their common enemy [the Ilkhanate], the Kipchack Mongols and the Mamluks entered into an alliance." Luisetto, p.157 against their common enemy the Ilkhanate. This alliance was both strategic, and also in terms of trade exchanges, as the Mamluks had been the Golden Horde's long-standing trade partner and ally in the Mediterranean.Mantran, Robert (Fossier, Robert, ed.) "A Turkish or Mongolian Islam" in The Cambridge Illustrated History of the Middle Ages: 1250-1520, p. 298
For their part, the Mongols of the Ilkhanate sought (unsuccessfully) an alliance with the Franks of Europe,Morgan, Mongols and the West but did form a Byzantine-Mongol alliance with the Christian Byzantine Empire.
Conflict between the Golden Horde and the Il-Khans
The two Western Mongol realms, the Golden Horde and the Il-Khanate, were already in open war. The roots of the conflict were related to battles between the descendants of Genghis Khan over the control of the Empire. The immediate successor to Genghis Khan was his son Ögedei, but the leadership was then taken by force by the descendants of Genghis' son Tolui. During the reign of Kublai Khan (son of Genghis' son Tolui), descendants of Genghis's other sons Ögedei, Chagatai, and Jochi sought to oppose the rule of Kublai. The Ilkhanate had been founded by Hulagu, another of Tolui's sons, who was therefore loyal to Kublai. The Golden Horde had been founded by Genghis' son Jochi, following the Mongol invasion of Central Asia. Genghis had designated several of the territories south of the Caucasus to Jochi, specifically Georgia, and the Seljukid Sultanate.Luisetto, p.155 Hulagu, with the backing of his brother the Great Khan Kublai, invaded and captured these territories in 1256, even installing his capital in the center of the disputed territories, at Maragha. Berke, the leader of the Golden Horde, could not tolerate this infringement of his inheritance, and a drawn-out conflict between the two Mongol realms continued well into the 14th century.The Mongols, David Morgan, p.144
Ethnic and religious affinities Various affinities led to a more or less natural alliance between the Mongols of the Golden Horde and the Mamluks of Egypt. The Mamluks' Empire had been founded by former slaves bought from the Kipchak territory of southern Russia, which was now an important segment of the Mongol Golden Horde. There were therefore already cultural affinities between large segments of the Mongol Horde and the ruling elite of Egypt."It is a fact of crucial importance that the Mamluks of Egypt and the Mongols of the Golden Horde were natural allies (…) simply because the ruling class of Egypt and an important and influential segment of the Golden Horde belonged in fact to the same ethnic group." A History of the Crusades, Kenneth Meyer Setton, p.527 Berke's Turkic subjects also spoke the same Turkic language as the Mamluks.Setton, p.527 Further, the Golden Horde, under Berke's leadership, was the first of the Mongol states to convert to Islam, which lent to solidarity with the Islamic realms to the south.By ultimately becoming Muslims, the Mongols of the Golden Horde conspicuously identified themselves with their Turkish subjects and with the people to the south, rather than with the Christian Russians to the North" Morgan, p.128 On the other hand, the Il-Khan rulers were highly favourable to Christianity, and did not commit to Islam until 1295, when the Ilkhan Ghazan, a descendant of Tolui, formerly converted when he took the throne."On the contrary, Hulagu, accompanied by Dokuz Khatun greatly favoured Christianity", Luisetto, p.155-156 Even after his conversion though, he continued to battle the Mamluks for control of Syria, while simultaneously seeking an alliance with Christian Europe.
Mamluk–Golden Horde rapprochement
The Golden Horde entered into a defensive alliance with the Mamluks in Egypt, with the agreement being that each realm would intervene if the other was attacked by the Ilkhanate."In order to fight their common enemy [the Ilkhanate], the Kipchack Mongols and the Mamluks entered into an alliance. This was based on a defensive rather than an offensive policy: if one of their territories was attacked, the second would fight for the other, on his own front, in order to create a diversion or weaken enough Persian troops so that their action would be stopped." Luisetto, p.157"Before invading Syria in 1299, Ghazan was forced to send troops in the Caucasus, in order to reinforce his Christian-Mongol troops. These were so many soldiers who could not fight in Palestine.", Luisetto, p.156 This required the Il-khan to devote forces to both his northern and southern borders, and never use all forces in a single battle. On multiple occasions, the forces of the Ilkhanate would start a campaign towards Syria in the south, only to be forced to recall troops within a few months because of attacks from the Golden Horde in the north.Luisetto, p.158
Timeline
First invasions (1244-1251) During the governorship of Bachu in Persia, the Mongolian army under Yisaur attacked Syria in 1244. The reasons for the attack are unclear, but it may have been in retaliation for the Syrian participation on the Seljuk side in the Battle of Köse Dağ.D. S. Benson The Mongol campaigns in Asia, p.179 In the autumn 1244, Yisaur concentrated the Mongol forces in the upper Tigris valley where they subjugated the Kurdish province of Akhlat. Moving across, the Mongolian army encountered no resistance and ravaged the area en route. The fortified cities were untaken in his advance because Yisaur was not prepared for siege assault. Passing through the territory of the city of Urfa, he crossed the Euphrates.
He marched directly to Aleppo but went as far as Hailan before the climate impaired his army's movements. Yisaur sent envoys to Aleppo to demand submission of tribute, which Malik agreed to pay. The same demand were sent to Bohemond V of Antioch who chose not to fight them instead of defiance.Jeremiah Curtin The Mongols: A history, p.178
Yisaur withdrew his force back up the Euphrates valley and received the submission of Malatya. In Egypt, Sultan as-Salih Ayyub decided to acquiesce to the results and made no attempt to raise an army to encounter the Mongols who had invaded his dominions in Syria.
In 1251, as an expediency to buy peace, Sultan an-Nasir Yusuf sent his representatives to Mongolia for the election of Möngke and agreed to make Syria a vassal state of the Mongol Empire.
Raids into Palestine and First Battle of Homs (1260)
In 1255, Hulagu sought to further expand the Empire into the Middle East under orders from his older brother, the Great Khan Möngke. Hulagu's forces subjugated multiple peoples along the way, most notably the center of the Islamic Empire, Baghdad, which was completely sacked in 1258, destroying the Abbasid Caliphate. From there, the Mongol forces proceeded into Syria.
In 1260, Egypt was under the control of the Bahri Mamluks, while most of the Levant (aside from the Crusader states) was still under the control of Ayyubid princes. The Mongols, for their part, had combined their forces with that of their Christian vassals in the region, the Georgians; the army of Cilician Armenia under Hethum I, King of Armenia; and the Franks of Bohemond VI of Antioch. In what is described by the 20th-century historians René Grousset and Lev Gumilev as the "yellow crusade" (Croisade Jaune), the combined forces captured the city of Aleppo in January, and then on March 1, 1260, under the Mongol Christian general Kitbuqa, took Damascus. The last Ayyubid king, An-Nasir Yusuf, was captured by the Mongols near Gaza in 1260. However, Hulagu promised him that he would appoint An-Nasir Yusuf as his viceroy in Syria.The Cambridge History of Egypt: Islamic Egypt, 640-1517, p.255 With the Islamic power center of Baghdad and Syria gone, the center of Islamic power transferred to the Mamluks in Cairo.
Hulagu's intention at that point was to continue south through Palestine to Egypt, to engage the Mamluks. However, Möngke died in late 1259, requiring Hulagu to return to Karakorum to engage in the councils on who the next Great Khan would be. Hulagu departed with the bulk of his forces, leaving only about 10,000 Mongol horsemen in Syria under Kitbuqa. Some of Kitbuqa's forces engaged in raids southwards towards Egypt, reaching as far as Gaza, where a Mongol garrison was established with 1,000 troops.
The Mamluks took advantage of the weakened state of the Mongol forces, and, negotiating a passive alliance with the remnants of the Crusader forces in Acre, advanced northwards to engage the Mongols at the pivotal Battle of Ain Jalut in September 1260. The Mamluks achieved a decisive victory, Kitbuqa was executed, and the battle established a high-water mark for the Mongol conquests. In previous defeats, the Mongols had always returned later to re-take the territory, but they were never able to avenge the loss at Ayn Jalut. The border of the Mongol Ilkhanate remained at the Tigris River for the duration of Hulagu's dynasty. Sultan An-Nasir and his brother were executed after Hulagu heard the news of the defeat of Kitbuqa at Ain Jalut.
In December 1260, Hulagu sent 6,000 troops back into Syria, but they were defeated at the First Battle of Homs.
Invasion of Upper Mesopotamia (1261-1265)