The Barons' Crusade achieved more territorial success than any mission since the First Crusade.
While often overshadowed by the lack of major military victories, the Barons' Crusade of 1239–1241 used shrewd diplomacy to expand the Kingdom of Jerusalem to its greatest extent since 1187. By playing warring Ayyubid factions against each other, these crusaders secured concessions that even the Sixth Crusade failed to obtain.
Initiated by Pope Gregory IX to bolster Christian control after the Sixth Crusade's truce expired in 1239, the Barons' Crusade was a fragmented endeavor. It lacked a unified command, consisting of two distinct waves: one led by King Theobald I of Navarre in 1239, and another by Richard of Cornwall in 1240. Despite the Pope's efforts to foster a universal Christian identity, the leadership remained divided, and the campaign was plagued by internal dissent. A disastrous, unauthorized raid at Gaza in November 1239, led by nobles like Henry of Bar, resulted in a crushing defeat and the subsequent loss of Jerusalem to an-Nasir Dawud of Transjordan.
However, the crusade's true success lay in the geopolitical maneuvering that followed. Theobald I exploited a civil war within the Ayyubid dynasty, negotiating with the Emir of Damascus, As-Salih Ismail, against the Sultan of Egypt, As-Salih Ayyub. This diplomatic gamble yielded significant territorial gains, including Bethlehem, Nazareth, and parts of Galilee. Ismail’s concessions were so controversial that he had to personally besiege a stronghold to force his own garrison to surrender it to the Christians. Theobald’s successor, Richard of Cornwall, arrived in October 1240 to finalize these truces and oversee the reconstruction of the castle at Ascalon, ultimately securing the release of prisoners captured during the earlier Gaza debacle.
The crusade’s territorial achievements were short-lived, however. By 1244, the Siege of Jerusalem and the subsequent Battle of La Forbie permanently crippled Christian military power in the region. Furthermore, the crusade’s lack of unity was underscored by Pope Gregory IX’s erratic attempts to redirect resources toward the Latin Empire of Constantinople. While Baldwin of Courtenay successfully captured the strategic site of Tzurulum in 1240, these efforts failed to stabilize the Latin Empire, which collapsed two decades later in 1261. Ultimately, the Barons' Crusade serves as a testament to the power of diplomacy in medieval warfare, even when the underlying political structure is deeply fractured.
Source: Barons' Crusade
