The Fourth Crusade

Learning Objective

  • Describe the failures of the Fourth Crusade


Crusader states

A number of mostly 12th- and 13th-century feudal states created by Western European crusaders in Asia Minor, Greece, and the Holy Land, and in the eastern Baltic area during the Northern Crusades.


People who holds beliefs or theories that are strongly at variance with established beliefs or customs, especially those held by the Roman Catholic Church.

Knights Templar

Among the wealthiest and most powerful of the Western Christian military orders; prominent actors in the Crusades.

Great Schism

The break of communion between what are now the Eastern Orthodox and Catholic churches, which has lasted since the 11th century.

Evolution of the Crusades

The Crusades were a series of religious wars undertaken by the Latin church between the 11th and 15th centuries. Crusades were fought for many reasons: to capture Jerusalem, recapture Christian territory, or defend Christians in non-Christian lands; as a means of conflict resolution among Roman Catholics; for political or territorial advantage; and to combat paganism and heresy.

The First Crusade arose after a call to arms in 1095 sermons by Pope Urban II. Urban urged military support for the Byzantine Empire and its Emperor, Alexios I, who needed reinforcements for his conflict with westward-migrating Turks in Anatolia. One of Urban’s main aims was to guarantee pilgrims access to the holy sites in the Holy Land that were under Muslim control. Urban’s wider strategy may have been to unite the eastern and western branches of Christendom, which had been divided since their split in 1054, and establish himself as head of the unified church. Regardless of the motivation, the response to Urban’s preaching by people of many different classes across Western Europe established the precedent for later crusades.

As a result of the First Crusade, four primary Crusader states were created: the Kingdom of Jerusalem, the County of Edessa, the Principality of Antioch, and the County of Tripoli. On a popular level, the First Crusade unleashed a wave of impassioned, pious Catholic fury, which was expressed in the massacres of Jews that accompanied the Crusades and the violent treatment of the “schismatic” Orthodox Christians of the east.

Under the papacies of Calixtus II, Honorius II, Eugenius III, and Innocent II, smaller-scale crusading continued around the Crusader states in the early 12th century. The Knights Templar were recognized, and grants of crusading indulgences to those who opposed papal enemies are seen by some historians as the beginning of politically motivated crusades. The loss of Edessa in 1144 to Imad ad-Din Zengi led to preaching for what subsequently became known as the Second Crusade. King Louis VII and Conrad III led armies from France and Germany to Jerusalem and Damascus without winning any major victories. Bernard of Clairvaux, who had encouraged the Second Crusade in his preachings, was upset with the violence and slaughter directed toward the Jewish population of the Rhineland.

In 1187 Saladin united the enemies of the Crusader states, was victorious at the Battle of Hattin, and retook Jerusalem. According to Benedict of Peterborough, Pope Urban III died of deep sadness on October 19, 1187, upon hearing news of the defeat. His successor, Pope Gregory VIII, issued a papal bull that proposed a third crusade to recapture Jerusalem. This crusade failed to win control of Jerusalem from the Muslims, but did result in a treaty that allowed trading and pilgrimage there for Europeans.

Crusading became increasingly widespread in terms of geography and objectives during the 13th century; crusades were aimed at maintaining political and religious control over Europe and beyond and were not exclusively focused on the Holy Land. In Northern Europe the Catholic church continued to battle peoples whom they considered pagans; Popes such as Celestine III, Innocent III, Honorius III, and Gregory IX preached crusade against the Livonians, Prussians, and Russians. In the early 13th century, Albert of Riga established Riga as the seat of the Bishopric of Riga and formed the Livonian Brothers of the Sword to convert the pagans to Catholicism and protect German commerce.

Fourth Crusade

Innocent III began preaching what became the Fourth Crusade in 1200 in France, England, and Germany, but primarily in France. The Fourth Crusade (1202–1204) was a Western European armed expedition originally intended to conquer Muslim-controlled Jerusalem by means of an invasion through Egypt. Instead, a sequence of events culminated in the Crusaders sacking the city of Constantinople, the capital of the Christian-controlled Byzantine Empire. The Fourth Crusade never came to within 1,000 miles of its objective of Jerusalem, instead conquering Byzantium twice before being routed by the Bulgars at Adrianople.

In January 1203, en route to Jerusalem, the majority of the Crusader leadership entered into an agreement with the Byzantine prince Alexios Angelos to divert to Constantinople and restore his deposed father as emperor. The intention of the Crusaders was then to continue to the Holy Land with promised Byzantine financial and military assistance. On June 23, 1203, the main Crusader fleet reached Constantinople. Smaller contingents continued to Acre.

In August 1203, following clashes outside Constantinople, Alexios Angelos was crowned co-emperor (as Alexios IV Angelos) with Crusader support. However, in January 1204, he was deposed by a popular uprising in Constantinople. The Western Crusaders were no longer able to receive their promised payments, and when Alexios was murdered on February 8, 1204, the Crusaders and Venetians decided on the outright conquest of Constantinople. In April 1204, they captured and brutally sacked the city and set up a new Latin Empire, as well as partitioned other Byzantine territories among themselves.

Byzantine resistance based in unconquered sections of the empire such as Nicaea, Trebizond, and Epirus ultimately recovered Constantinople in 1261.

The Fourth Crusade is considered to be one of the final acts in the Great Schism between the Eastern Orthodox Church and Roman Catholic Church, and a key turning point in the decline of the Byzantine Empire and Christianity in the Near East.


Conquest of Constantinople. A Medieval painting of the Conquest of Constantinople by the Crusaders in 1204.

Later Crusades

After the failure of the Fourth Crusade to hold Constantinople or reach Jerusalem, Innocent III launched the first crusade against heretics, the Albigensian Crusade, against the Cathars in France and the County of Toulouse. Over the early decades of the century the Cathars were driven underground while the French monarchy asserted control over the region. Andrew II of Hungary waged the Bosnian Crusade against the Bosnian church, which was theologically Catholic but in long-term schism with the Roman Catholic Church. The conflict only ended with the Mongol invasion of Hungary in 1241. In the Iberian peninsula, Crusader privileges were given to those aiding the Templars, the Hospitallers, and the Iberian orders that merged with the Order of Calatrava and the Order of Santiago. The papacy declared frequent Iberian crusades, and from 1212 to 1265 the Christian kingdoms drove the Muslims back to the Emirate of Granada, which held out until 1492, when the Muslims and Jews were expelled from the peninsula.

Around this time, popularity and energy for the Crusades declined. One factor in the decline was the disunity and conflict among Latin Christian interests in the eastern Mediterranean. Pope Martin IV compromised the papacy by supporting Charles of Anjou, and tarnished its spiritual luster with botched secular “crusades” against Sicily and Aragon. The collapse of the papacy’s moral authority and the rise of nationalism rang the death knell for crusading, ultimately leading to the Avignon Papacy and the Western Schism. The mainland Crusader states were extinguished with the fall of Tripoli in 1289 and the fall of Acre in 1291.

Centuries later, during the middle of the 15th century, the Latin church tried to organize a new crusade aimed at restoring the Eastern Roman or Byzantine Empire, which was gradually being torn down by the advancing Ottoman Turks. The attempt failed, however, as the vast majority of Greek civilians and a growing part of their clergy refused to recognize and accept the short-lived near-union of the churches of East and West signed at the Council of Florence and Ferrara by the Ecumenical patriarch Joseph II of Constantinople. The Greek population, reacting to the Latin conquest, believed that the Byzantine civilization that revolved around the Orthodox faith would be more secure under Ottoman Islamic rule. Overall, religious-observant Greeks preferred to sacrifice their political freedom and political independence in order to preserve their faith’s traditions and rituals in separation from the Roman See.

In the late-14th and early-15th centuries, “crusades” on a limited scale were organized by the kingdoms of Hungary, Poland, Wallachia, and Serbia. These were not the traditional expeditions aimed at the recovery of Jerusalem but rather defensive campaigns intended to prevent further expansion to the west by the Ottoman Empire.