The Crusades

In November 1095, at a church council in Clermont in central France, Pope Urban II preached a sermon calling on the knights of Latin Christendom to march east and recover Jerusalem and the Holy Land from Muslim rule. The appeal drew on a request from the Byzantine emperor Alexios I Komnenos for military help against the Seljuk Turks, but Urban's own version of the call went further, framing the campaign as an armed pilgrimage that would earn its participants a plenary indulgence, full remission of the temporal punishment owed for confessed sin. Reports of the sermon describe the crowd interrupting with cries of Deus vult, God wills it, which became the movement's rallying cry.

What followed surprised even the pope. Alongside the organized noble armies that set out through 1096 and 1097, an unauthorized and poorly provisioned popular movement known as the People's Crusade, led by the preacher Peter the Hermit, marched ahead and was largely destroyed by Seljuk forces in Anatolia before the main armies arrived. The knightly crusade fared better, taking Nicaea in 1097, winning a hard fought siege at Antioch in 1098, and finally storming Jerusalem in July 1099, where the capture was followed by a massacre of the city's Muslim and Jewish inhabitants that later chroniclers, including some sympathetic to the crusade, recorded as extreme even by the standards of medieval siege warfare. The victors divided the conquered territory into four Crusader states, with the Kingdom of Jerusalem as the most prominent, beginning two centuries of a Latin Christian presence in the Levant that the First Crusade had neither been guaranteed nor, on its own, been able to make permanent.

The clearest sign that crusading had become an instrument rather than a single campaign is the Fourth Crusade of 1202 to 1204, which never reached the Holy Land at all. Diverted first to the Christian city of Zara on the Adriatic at the demand of Venice, which had financed the fleet and wanted a rival port neutralized, the crusader army was then drawn into a succession dispute over the Byzantine throne. What began as an attempt to restore a deposed claimant ended in the storming and sack of Constantinople itself in April 1204, an Orthodox Christian capital, with churches looted, relics carried off to the West and a Latin emperor installed in place of the Byzantine one. The event poisoned relations between the Latin and Orthodox churches for centuries and is widely treated by historians as the clearest case of the crusading ideal outrunning its own stated purpose.

Later crusades kept widening the target list. The papacy authorized the Albigensian Crusade from 1209 against the Cathars of Languedoc in southern France, an internal war against a Christian heresy rather than a foreign campaign, and the Northern Crusades carried the same institutional machinery, preaching, vows and indulgences, against pagan peoples along the Baltic coast well into the fourteenth century. By the time the last mainland Crusader stronghold, Acre, fell to the Mamluks in 1291, the word crusade had already outgrown the Jerusalem campaign that coined it, and the practice of declaring one continued off and on for centuries afterward, invoked against the Ottoman advance into Europe and, in political rhetoric rather than the historical sense, into the present day.