A Byzantine–Mongol alliance occurred during the end of the 13th and the beginning of the 14th century between the Byzantine Empire and the Mongol Empire. Byzantium actually tried to maintain friendly relations with both the Golden Horde and the Ilkhanate realms, who were often at war with each other. The alliance involved numerous exchanges of presents, military collaboration and marital links, but dissolved in the middle of the 14th century.
Soon after the Battle of Kose Dag in 1243, the Empire of Trebizond surrendered to the Mongol Empire while the court of Nicaea put its fortresses in order. In the early 1250s, the Latin emperor of Constantinople Baldwin II sent an embassy to Mongolia in the person of the knight Baudoin de Hainaut, who, following his return, met in Constantinople with the departing William of Rubruck. William of Rubruck also noted that he met an envoy of John III Doukas Vatatzes, emperor of Nicaea, at the court of Möngke Khan in circa 1253.
Alliance under Michael VIII (1263–1282)
Emperor Michael VIII Palaiologos, after re-establishing Byzantine Imperial rule, established an alliance with the Mongols, who themselves were highly favourable to Christianity, many of them being Nestorian Christians.
He signed a treaty in 1263 with the Mongol Khan of the Kipchak (the Golden Horde), and he married two of his daughters (conceived through a mistress, a Diplovatatzina) to Mongol kings: Euphrosyne Palaiologina, who married Nogai Khan of the Golden Horde, and Maria Palaiologina, who married Abaqa Khan of Ilkhanid Persia.
According to a 1267 letter by Pope Clement IV from Viterbo, Abaqa had agreed to combine forces with his father-in-law Michael VIII to help the Latins in the Holy Land, in preparation for the Eighth Crusade (the second of Louis IX):
"The kings of France and Navarre, taking to heart the situation in the Holy Land, and decorated with the Holy Cross, are readying themselves to attack the enemies of the Cross. You wrote to us that you wished to join your father-in-law (the Greek emperor Michael VIII Palaiologos) to assist the Latins. We abundantly praise you for this, but we cannot tell you yet, before having asked to the rulers, what road they are planning to follow. We will transmit to them your advice, so as to enlighten their deliberations, and will inform your Magnificence, through a secure message, of what will have been decided."—1267 letter from Pope Clement IV to Abaqa
In 1265 Berke Khan sent the Golden Horde army under Noghai to Thrace, prompting to force the Byzantine to release the Mamluk envoy and the former Seljuk Sultan Kaykaus II. According to Egyptian sources, Michael agreed to send fabrics to the Mongol Khan in Russia. When Michael realized the importance of the Mongols and became an ally of Noghai, he used his help to defend himself against Bulgaria when it tried to attack the Byzantine Empire in 1273 and 1279. A group of 4,000 Mongol soldiers were dispatched to Constantinople in 1282, just before the death of Michael, to fight against the despot of Thessaly.
Alliance under Andronikos II (1282–1328)
After 1295, Andronikos II offered Ghazan a marital alliance, in exchange for Mongol help to fight against the Turcomans at the Oriental frontier of the Byzantine Empire. Ghazan accepted the offer and promised to stop the incursions. The death of Ghazan in 1308 was mourned by the Byzantines.
This alliance would continue under Ghazan's successor, Oljeitu. In 1305 Ilkhan Oljeitu promised Andronicus II 40,000 men, and in 1308 dispatched 30,000 men to recover many Byzantine towns in Bithynia. Andronicus II gave daughters in marriage to Toqto'a, as well as his successor Uzbek (1312–1341), but relations turned sour at the end of Andonicus's reign and the Mongols mounted raids on Thrace between 1320 to 1324, until the Byzantine port of Vicina Macaria was occupied by the Mongols.
End of friendly relations
- Shepherd, William R. Historical Atlas, 1911.
- Sicker, p. 132.
- Dagron et al., p. 309. "…agreed to prolong the Byzantine-Mongol (Iranian) alliance."
- Jackson, pp. 202–203. "From 1273 Michael allied with Noghai, giving him an illegitimate daughter in marriage and using him as a means to put pressure on Bulgaria."
- A. A. Vasiliev History of the Byzantine Empire, 324-1453, p.531
- Richard, p. 377.
- Richard, p. 453. "The sustained attacks by the Sultan Baibars (…) rallied the Occidentals to this alliance [with the Mongols], to which the Mongols also convinced the Byzantines to adhere."
- Cambridge, p. 304.
- Canal and Runciman, p. 320.
- Quoted in Grousset, p. 644.
- Jackson, pp. 202-203.
- Jackson, p. 203.
- Heath and McBride, p. 24.
- Luisetto, pp. 144-145, referencing Pachymeres.
- Luisetto, p. 145.
- Heath and McBride, pp. 24–33.
- Gilbert Dagron, Brigitte Mondrain, Vincent Deroche, and Jean-Claude Cheynet. XXe Congrès international des études Byzantines: Collège de France - Sorbonne, 19 - 25 août 2001: pré-actes: XXe Congrès international des études Byzantines, Collège de France-Sorbonne, 19-25 août 2001. Comité d'organization du XXe Congrès international des études Byzantines, Collège de France, 2001, ISBN 2-9517158-0-3.
- Heath, Ian and McBride, Angus. Byzantine Armies: AD 1118–1461. Osprey Publishing, 1995, ISBN 1-85532-347-8.
- Nicol, Donald MacGillivray. The Last Centuries of Byzantium, 1261–1453. Cambridge University Press, 1993, ISBN 0-521-43991-4.
- Oxford Dictionary of Byzantium. Oxford University Press, 1991.
- Cheynet, Jean-Claude and Vannier, Jean-François. "Les premiers Paléologues". Etudes prosopographiques. Publications de la Sorbonne, 1986, ISBN 2-85944-110-7.
- Richard, Jean. Histoire des Croisades [History of the Crusades]. Paris: Editions Fayard, 1996.
- Jackson, Peter. The Mongols and the West, 1221-1410. Pearson Longman, 2005, ISBN 0-582-36896-0.
- Luisetto, Frédéric. Arméniens & autres Chrétiens d'Orient sous la domination Mongole (in French). Librairie Orientaliste Paul Geuthner S.A., 2007, ISBN 978-2-7053-3791-9.
- Sicker, Martin. The Islamic World in Ascendancy: From the Arab Conquests to the Siege of Vienna. Greenwood Publishing Group, 2000, ISBN 0-275-96892-8.
- Canal, Denis-Armand and Runciman, Steven. Histoire des Croisades [History of the Crusades]. Editions Dagorno, 1998, ISBN 2-910019-45-4.
- This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.