Attempting to form an alliance with the Mongol Empire, Louis IX of France met with two of their envoys while en route to the Seventh Crusade.

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—Western Europeans, and those in the Levantine Crusader states—were open to the idea of support from the East, in part owing to the long-running legend of the mythical 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. The Franks and Mongols also shared a common enemy in the Muslims. However, despite many messages, gifts, and emissaries over the course of several decades, the often-proposed alliance never came to fruition.

Louis IX, also known as Saint Louis, was King of France from 1226 until his death in 1270. He is widely recognized as the most distinguished of the Direct Capetians. Following the death of his father, Louis VIII, he was crowned in Reims at the age of 12. His mother, Blanche of Castile, effectively ruled the kingdom as regent until he came of age, and continued to serve as his trusted adviser until her death. During his formative years, Blanche successfully confronted rebellious vassals and championed the Capetian cause in the Albigensian Crusade, which had been ongoing for the past two decades.

The Seventh Crusade (1248–1254) was the first of the two Crusades led by Louis IX of France. Also known as the Crusade of Louis IX to the Holy Land, it aimed to reclaim the Holy Land by attacking Egypt, the main seat of Muslim power in the Near East. The Crusade was conducted in response to setbacks in the Kingdom of Jerusalem, beginning with the loss of the Holy City in 1244, and was preached by Innocent IV in conjunction with a crusade against emperor Frederick II, Baltic rebellions and Mongol incursions. After initial success, the crusade ended in defeat, with most of the army – including the king – captured by the Muslims.