Several attempts at a military alliance between the Frankish Crusaders and the Mongol Empire against the Islamic caliphates, their common enemy, were made by various leaders among them during the 13th century. Such an alliance might have seemed an obvious choice: the Mongols were already sympathetic to Christianity, given the presence of many influential Nestorian Christians in the Mongol court. The Franks in both Western Europe and the Levantine Crusader statesMany people in the East used the word "Frank" to denote a European of any variety. See also Farang. were open to the idea of support from the East, in part owing to the long-running legend of Prester John, an Eastern king in an Eastern kingdom who many believed would one day come to the assistance of the Crusaders in the Holy Land.Jackson. Mongols and the West. p. 4. "The failure of Ilkhanid-Western negotiations, and the reasons for it, are of particular importance in view of the widespread belief in the past that they might well have succeeded." The Franks and Mongols also shared a common enemy in the caliphates. However, despite many messages, gifts, and emissaries over the course of several decades, the often-proposed alliance never came to fruition.Atwood. "Western Europe and the Mongol Empire" in Encyclopedia of Mongolia and the Mongol Empire. p. 583. "Despite numerous envoys and the obvious logic of an alliance against mutual enemies, the papacy and the Crusaders never achieved the often-proposed alliance against Islam".Ryan. pp. 411–421.
Contact between Europeans and Mongols began around 1220, with occasional messages from the papacy and European monarchs to Mongol leaders such as the Great Khan, and subsequently to the Ilkhans in Mongol-conquered Persia. Communications tended to follow a recurring pattern: the Europeans asked the Mongols to convert to Western Christianity, while the Mongols responded with demands for submission and tribute. The Mongols had already conquered many Christian and Muslim states in their advance across Asia, and after destroying the Nizaris of Alamut and the Muslim Abbasid and Ayyubid dynasties, for the next few generations fought the remaining Islamic power in the region, the Egyptian Mamluks. Hethum I, king of the Christian state of Cilician Armenia, had submitted to the Mongols in 1247, and strongly encouraged other monarchs to engage in a Christian–Mongol alliance, but was only able to persuade his son-in-law, Prince Bohemond VI of the Crusader state of Antioch, who submitted in 1260. Other Christian leaders such as the Crusaders of Acre were more mistrustful of the Mongols, perceiving them as the most significant threat in the region. The Barons of Acre therefore engaged in an unusual passive alliance with the Muslim Mamluks, allowing Egyptian forces to advance unopposed through Crusader territory to engage and defeat the Mongols at the pivotal Battle of Ain Jalut in 1260.
European attitudes began to change in the mid-1260s, from perceiving the Mongols as enemies to be feared, to potential allies against the Muslims. The Mongols sought to capitalize on this, promising a re-conquered Jerusalem to the Europeans in return for cooperation. Attempts to cement an alliance continued through negotiations with many leaders of the Mongol Ilkhanate in Persia, from its founder Hulagu through his descendants Abaqa, Arghun, Ghazan, and Öljaitü, but without success. The Mongols invaded Syria several times between 1281 and 1312, sometimes in attempts at joint operations with the Franks, but the considerable logistical difficulties involved meant that forces would arrive months apart, never able to coordinate activities in any effective way. The Mongol Empire eventually dissolved into civil war, and the Mamluks successfully recaptured all of Palestine and Syria from the Crusaders. After the fall of Acre in 1291, the remaining Crusaders retreated to the island of Cyprus. They made a final attempt to establish a bridgehead at the small island of Ruad off the coast of Tortosa, again in an attempt to coordinate military action with the Mongols, but the plan failed, and the Muslims responded by besieging the island. With the Fall of Ruad in 1302, the Crusaders lost their last foothold in the Holy Land.Demurger. "The Isle of Ruad". The Last Templar. pp. 95–110.
Modern historians debate whether an alliance between the Franks and Mongols would have been successful in shifting the balance of power in the region, and if it would have been a wise choice on the part of the Europeans.See Abate and Marx. pp. 182–186, where the question debated is "Would a Latin-Ilkhan Mongol alliance have strengthened and preserved the Crusader States? Traditionally, the Mongols tended to see outside parties as either subjects or enemies, with little room in the middle for a concept such as allies.Jackson. Mongols and the West. p. 46. See also pp. 181–182. "For the Mongols the mandate came to be valid for the whole world and not just for the nomadic tribes of the steppe. All nations were de jure subject to them, and anyone who opposed them was thereby a rebel (bulgha). In fact, the Turkish word employed for 'peace' was that used also to express subjection ... There could be no peace with the Mongols in the absence of submission."Jackson. Mongols and the West. p. 121. "[The Mongols] had no allies, only subjects or enemies".
Background (1209–1244)
There had long been rumors and expectations among Western Europeans that a great Christian ally would come from the East. These rumors circulated as early as the First Crusade (1096–1099), and usually surged in popularity after the Crusaders lost a battle. A legend arose about a figure known as Prester John, who lived in far-off India, Central Asia, or perhaps even Ethiopia. This legend developed a life of its own, and some individuals who came from the East were greeted with expectations that they might be forces sent by the long-awaited Prester John. In 1210, news reached the West of the battles of the Mongol Kuchlug (d. 1218), leader of the largely Christian tribe of the Naimans. Kuchlug's forces had been battling the powerful Khwarezmian Empire, whose leader was the Muslim Muhammad II of Khwarezm. Rumors circulated in Europe that Kuchlug was the mythical Prester John, again battling the Muslims in the East.Foltz. pp. 111–112.
During the Fifth Crusade (1213–1221), as the Christians were unsuccessfully laying siege to the Egyptian city of Damietta, the legend of Prester John became conflated with the reality of Genghis Khan's rapidly expanding empire. Mongol raiding parties were beginning to invade the eastern Islamic world in Transoxania and Persia in 1219–1221.Amitai. "Mongol raids into Palestine (AD 1260 and 1300)". p. 236. Rumors circulated among the Crusaders that a "Christian king of the Indies", a King David who was either Prester John or one of his descendants, had been attacking Muslims in the East and was on his way to help the Christians in their crusades.Knobler. pp. 181–197. In a letter dated , Pope Honorius III even commented about "forces coming from the Far East to rescue the Holy Land".Quoted in Runciman. p. 246.
After the division of the Mongol Empire in 1259, his empire was divided by his descendants into four sections or Khanates, which degenerated into civil war, although the Yuan emperors held the nominal title of khagan of the empire.
The northwestern Kipchak Khanate, known as the Golden Horde, expanded towards Europe, primarily via Hungary and Poland, while its leaders simultaneously opposed the rule of their cousins back at the Mongol capital. The southwestern section, known as the Ilkhanate, was under the leadership of Genghis Khan's grandson Hulagu. He continued to support his brother, the Great Khan, and was therefore at war with the Golden Horde, while at the same time continuing an advance towards Persia and the Holy Land.Morgan. The Mongols. pp. 133–138.
Papal overtures (1245–1248)
The first official communications between Western Europe and the Mongol Empire occurred between Pope Innocent IV (fl. 1243–1254) and the Great Khans, via letters and envoys that were sent overland and could take years to arrive at their destination. The communications initiated what was to become a regular pattern in European–Mongol communications: the Europeans would ask the Mongols to convert to Christianity, and the Mongols would respond with demands for submission.Richard. p. 422. "In all the conversations between the popes and the il-khans, this difference of approach remained: the il-khans spoke of military cooperation, the popes of adhering to the Christian faith."
The Mongol invasion of Europe ended in 1242, in part because of the death of the Great Khan Ögedei, successor to Genghis Khan. When one Great Khan died, Mongols from all parts of the empire were recalled to the capital to decide who should be the next Great Khan.Jackson. Mongols and the West. p. 72. In the meantime, the Mongols' relentless march westward had displaced the Khawarizmi Turks, who themselves moved west, eventually allying with the Ayyubid Muslims in Egypt.Tyerman. pp. 770–771. Along the way, the Ayyubids took Jerusalem from the Christians in 1244. After the subsequent loss at the Battle of La Forbie, Christian kings began to prepare for a new crusade (the Seventh Crusade), declared by Pope Innocent IV in June 1245 at the First Council of Lyon.Riley-Smith. pp. 289–290.Tyerman. p. 772. The loss of Jerusalem caused some Europeans to look to the Mongols as potential allies of Christendom, provided the Mongols could be converted to Western Christianity. In March 1245, Pope Innocent IV had issued multiple papal bulls, some of which were sent with an envoy, the Franciscan John of Plano Carpini, to the "Emperor of the Tartars". In a letter now called the Cum non solum, Pope Innocent expressed a desire for peace, and asked the Mongol ruler to become a Christian and to stop killing Christians.Jackson. Mongols and the West. p. 90. However, the new Great Khan Güyük, who had been installed at Karakorum in 1246, replied only with a demand for the submission of the pope, and a visit from the rulers of the West in homage to Mongol power:Morgan. The Mongols. p. 102.
A second mission sent in 1245 by Pope Innocent was led by the Dominican Ascelin of Lombardia,Jackson. Mongols and the West. p. 88. who met with the Mongol commander Baiju near the Caspian Sea in 1247. Baiju, who had plans to capture Baghdad, welcomed the possibility of an alliance and sent a message to Rome via his envoys Aïbeg and Serkis. They then returned a year later with Pope Innocent's letter, Viam agnoscere veritatis, in which he appealed to the Mongols to "cease their menaces".Sinor. "Mongols in Western Europe". p. 522. "The Pope's reply to Baidju's letter, Viam agnoscere veritatis, dated November 22, 1248, and probably carried back by Aibeg and Sargis." Note that Sinor refers to the letter as "Viam agnoscere" though the actual letter uses the text "Viam cognoscere".Jackson. Mongols and the West. p. 89.
Christian vassals