The Crusades were a series of military campaigns launched by the papacy between 1095 and 1291 against Muslim rulers for the recovery and defence of the Holy Land, as part of a wider crusading movement. The First Crusade was proclaimed by Pope Urban II at the Council of Clermont in November 1095—a call to arms for Christians to reconquer Jerusalem from the Muslims, with promises of spiritual reward. By this time, the papacy's position as head of the Catholic Church had strengthened, and earlier conflicts with secular rulers and wars on the frontiers of Western Christendom had prepared it for the direction of armed force in religious causes. The successes of the First Crusade led to the establishment of four Crusader states in the Levant—the Kingdom of Jerusalem, the Principality of Antioch, and the counties of Tripoli and Edessa—whose defence required further expeditions from Catholic Europe. The organisation of such large-scale campaigns demanded complex religious, social, and economic institutions, including crusade indulgences, military orders, and the taxation of clerical income. Over time, the crusading movement expanded to include campaigns against pagans, Christian dissidents, and other enemies of the papacy, promoted with similar spiritual rewards and continuing into the 18th century.
The Crusade of 1101, the earliest papally sanctioned expedition inspired by the First Crusade, ended in disastrous defeats. For several decades thereafter, only smaller expeditions reached the Holy Land, yet their role in consolidating and expanding the Crusader states was pivotal. The fall of Edessa, the capital of the first Crusader state, prompted the Second Crusade, which failed in 1148. Its failure reduced support for crusading across Latin Christendom, leaving the Crusader states unable to resist Saladin's expansion. Having united Egypt and Muslim Syria under his rule, Saladin destroyed their combined armies at the Battle of Hattin in 1187. The Crusader states survived largely owing to the Third Crusade, a major campaign against Saladin, though Jerusalem remained under Muslim control. Initially directed against Egypt, the Fourth Crusade was diverted to the Byzantine Empire, culminating in the Sack of Constantinople and the establishment of the Latin Empire in 1204. The Fifth Crusade again targeted Egypt but failed to conquer it in 1219–21. By this period, crusade indulgences could also be obtained through other campaigns—such as the Iberian, Albigensian, and Northern Crusades—thereby diminishing enthusiasm for expeditions in the eastern Mediterranean.
Jerusalem was regained through negotiation during the Sixth Crusade in 1229, and in 1239–41 the Barons' Crusade restored much of the territory the Crusader states had lost. However, the Sack of Jerusalem by Muslim freebooters soon ended Crusader rule in the Holy City. Louis IX of France launched two major campaigns—the Seventh Crusade against Egypt in 1248–51 and the Eighth Crusade against Tunis in 1270—both of which ended in failure. In place of the large-scale passagium generale, the smaller passagium particulare became the predominant form of crusading campaigns in the late 13th century. The Crusader states, however, were unable to withstand the advance of the Mamluks. Having reunited Egypt and Muslim Syria by 1260, they went on to attack the Crusader states, capturing the Crusaders' last mainland strongholds in 1291. Although plans for the reconquest of the Holy Land continued to be made in the following decades, only the Alexandrian Crusade briefly revived crusading activity in the region in 1365.
Terminology
The Crusades were military campaigns undertaken by Western Christians to reclaim the Holy Land, or Palestine, from Muslim control between the 11th and 13th centuries. Launched by the papacy with promises of spiritual reward, they were occasionally accompanied by unauthorised movements—driven by popular zeal—commonly referred to as popular crusades. In scholarly usage, the term is frequently applied more broadly to include papally authorised conflicts in other regions, conducted within the wider framework of the crusading movement, including the Iberian, Northern and Albigensian Crusades.
Terminology evolved gradually, primarily reflecting the close association between the Crusades and Christian pilgrimage. Early usage favoured terms denoting mobility—iter ('journey'), expeditio ('expedition'), passagium ('passage')—typically accompanied by references to the intended destination, such as the Church of the Holy Sepulchre in Jerusalem. Other early expressions invoked the cross (crux), and by around 1250, canon lawyers were distinguishing between campaigns in the Holy Land—crux transmarina ('the cross overseas')—and those within Europe—crux cismarina ('the cross this side of the sea'). Participants, who traditionally sewed a cross onto their garments, came to be known as crucesignati ('those signed with the cross').
Vernacular terminology reflected the ritual of "taking the cross". The earliest attested form, crozada, appeared in Spain in 1212. The Middle English croiserie, derived from Old French, emerged in the 13th–14th centuries, later supplanted by forms such as croisade and crusado, both influenced by Spanish through French. The modern term crusade was established by 1706. The medievalist Thomas Asbridge notes that the term's conventional use by historians imposes "a somewhat misleading aura of coherence and conformity" on the earliest crusading efforts.
Background
Sites linked to Jesus's ministry became popular pilgrimage destinations in Roman Palestine. Christian emperors built churches at these locations, including the Church of the Holy Sepulchre, marking Jesus's crucifixion and resurrection in Jerusalem. In 395, the Roman Empire split into eastern and western halves. The Western Roman Empire had fragmented into smaller kingdoms by 476, while the Eastern Roman (Byzantine) Empire persisted, though it lost vast territories to the rising Islamic Caliphate in the 7th century. Jerusalem fell to Caliph Umar in 638. Islamic expansion, motivated by jihad (holy war), reached Western Europe with the Muslim conquest of much of the Iberian Peninsula after 711. Christians under Muslim rule were dhimmi—legally protected but socially subordinate. Islam's ideological unity fractured over disputes about leadership. The Shi'a believed authority belonged to the descendants of Muhammad's cousin and son-in-law, Ali, while the Sunni majority rejected the Alids' hereditary claim. By the mid-10th century, three rival caliphates had emerged: the Umayyads in al-Andalus (Muslim Spain), the Shi'ite Fatimids in Egypt, and the Abbasids in the Middle East.
To Muslim observers, such as Ibn Khordadbeh, the remote and less developed Western Europe was merely a source of slaves and raw materials. However, between c. 950 and c. 1070, drought and cold spells across North Africa, the Middle East, and Central Asia led to famine and migration. Interfaith tensions escalated, culminating in the temporary destruction of the Holy Sepulchre in 1009. From the 1040s, nomadic Turkomans disrupted the Middle East. In 1055, their leader Tughril I of the Seljuk clan assumed authority within the Abbasid Caliphate with Caliph Al-Qa'im's consent. Tughril's nephew Alp Arslan crushed the Byzantines at the Battle of Manzikert in 1071, opening Anatolia to Turkoman migration. The Seljuk Empire emerged as a loose federation of provinces ruled by Seljuk princes, Turkoman warlords and Arab emirs. As Byzantine control collapsed, Armenian and Greek strongmen took over frontier cities and fortresses.
From the mid-9th century, central authority in Western Europe weakened, and local lords gained power, commanding heavily armoured knights and holding castles. Their territorial disputes made warfare a regular feature across regions. To protect church property and unarmed groups, church leaders launched the Peace of God movement, threatening offenders with excommunication. As sins permeated daily life, Christians feared damnation. Sinners were expected to confess and undertake priestly prescribed penance. Thousands made the penitential journey to Jerusalem, though attacks on pilgrims became increasingly frequent.
From c. 1000, the Medieval Warm Period favoured Western Europe, spurring economic and population growth. Within a century, Italian merchants supplanted their Muslim and Jewish rivals as the leading force in Mediterranean trade. In 1031, al-Andalus fragmented into taifas—smaller kingdoms—that could not resist the Reconquista—the expansion of the northern Christian states—prompting intervention by the radical Almoravids from the Maghreb. In southern Italy, Norman warriors from northern France founded principalities and completed the conquest of Muslim Sicily by 1091.
In the mid-11th century, clerics promoting the "liberty of the Church" rose to power in Rome, banning simony and clerical marriage. The popes, regarded as successors to Saint Peter in Rome, claimed supremacy over Christendom, but Eastern Christian leaders rejected this. Combined with long-standing liturgical and theological differences, this led to mutual excommunications in 1054 and ultimately the division between the Catholic West and Orthodox East. Reformist clerics' rejection of lay control triggered the Investiture Controversy with secular powers. Popes had already courted allies by offering spiritual rewards, and the Controversy revived interest in the theology of just war, first articulated by Augustine in the 5th century. Theologians, under Pope Gregory VII's auspices, concluded that dying in a just war equated to martyrdom. Still, the idea of penitential warfare drew sharp criticism from anti-papal figures like Sigebert of Gembloux.
First Crusade
By the late 11th century, the development of Christian just war theory, increasing aristocratic piety, and the popularity of penitential journeys to the Holy Land created a context for armed pilgrimages. Strengthened by the church reforms, the papacy was well positioned to channel anxiety over sin and hopes of remission into a papally orchestrated war. In 1074, Gregory VII was the first pope to plan a campaign against the Turkomans, though it was never launched. In March 1095, his successor, Urban II, received envoys from Emperor Alexios I Komnenos, who requested military aid at the Council of Piacenza.
By this time, the Seljuk Empire had descended into civil war following the deaths of Vizier Nizam al-Mulk and Sultan Malik-Shah I in 1092. Malik-Shah's brother Tutush I contested the succession of Malik-Shah's son Berkyaruq. Although Tutush was killed in battle in 1095, his sons Ridwan and Duqaq, seized control of the Syrian cities of Aleppo and Damascus, respectively, while Tutush's former mamluk (slave soldier), Yaghi-Siyan, maintained his rule over Antioch. In Anatolia, the breakaway Seljuk prince Kilij Arslan I founded the independent Sultanate of Rum, while an autonomous Turkoman clan, the Danishmendids, seized control of the north.
Meanwhile, Fatimid Egypt faced its own succession crisis after the deaths of Caliph al-Mustansir and his vizier al-Jamali. Al-Jamali's son and successor al-Afdal Shahanshah installed al-Mustansir's youngest son al-Musta'li as caliph bypassing the eldest son Nizar. Although Nizar was murdered, his supporters rejected al-Musta'li's legitimacy and established a new branch of radical Shi'a Islam—the Nizaris, also known as the Assassins.
Council of Clermont and its aftermath
In July 1095, Pope Urban began a tour of France, negotiating with local elites, and ending with the Council of Clermont. Here, on 27 November, he announced a military campaign against the Turkomans. According to most accounts, he urged military support for eastern Christians, promising spiritual rewards, and condemning knightly violence. Accounts differ on whether he promised reduced penance or full remission of sin. Urban's appeal reportedly prompted the crowd to cry Deus vult! ('God wills it!'). The ritual of "taking the cross" was introduced on the spot, with Bishop Adhemar of Le Puy setting the precedent. He was soon appointed papal legate.
Urban held further councils in France, and set 15 August—two weeks after the harvest began—as the campaign's start date. His message spread mainly through those present at Clermont, leaving much of Western Europe unaware of the crusade. He also urged Catalan counts not to join, granting them equal spiritual rewards for fighting the Almoravids, marking an early instance of crusading in Iberia.
People's Crusade
Pope Urban sought to restrict enlistment to trained warriors, but popular enthusiasm proved uncontrollable. The charismatic Peter the Hermit preached in regions Urban had avoided, reportedly bearing a heavenly letter urging the expulsion of "pagans" from the Holy Land. He attracted thousands of peasants and townsfolk, alongside some nobles such as Walter Sans Avoir. In Germany, the preachers Folkmar and Gottschalk assembled similar groups.
Several contingents departed before the harvest, from March 1096. Walter and Peter each led forces of 10,000–15,000. While travelling, Peter threatened Jewish communities in pursuit of provisions. King Coloman of Hungary granted market access, but during their passage the host, by then c. 20,000 people, plundered the border town of Zemun. Entering Byzantine territory in June, their continued looting provoked imperial raids, causing severe losses. Meanwhile, Folkmar and Gottschalk's 15,000-strong host was destroyed by Coloman on Hungary's western frontier in July. A parallel rising under the Swabian count Emicho launched the anti-Jewish Rhineland massacres in western Germany, beginning at Speyer on 3 May 1096. Despite episcopal efforts at protection, his force spread anti-semitic violence until Hungarian troops dispersed it in mid-July.
Walter reached Constantinople on 20 July, Peter on 1 August. Distrustful of their disorder, Emperor Alexios shipped them across the Bosporus to Anatolia. Germans captured the Seljuk fortress of Xerigordos, but it was retaken by the Turkomans on 29 September. Kilij Arslan destroyed the crusaders at Civetot on 21 October; Peter survived with a few followers.
Princes' Crusade
No crowned ruler joined the First Crusade, largely because of tensions with the Church. The first major noble to depart was Hugh of Vermandois, brother of King Philip I of France. Godfrey of Bouillon, Duke of Lower Lorraine, set off in August 1096, followed by Bohemond of Taranto, a veteran of anti-Byzantine campaigns, in October, and Raymond of Saint-Gilles, Count of Toulouse, who led the largest force. Other leaders included Robert Curthose, Duke of Normandy; Stephen of Blois; and Robert II of Flanders. Their armies, as the historian Thomas Madden notes, were "a curious mix of rich and poor, saints and sinners", motivated by both faith and gain. As a knight's participation could cost four years' income, it was often financed through loans or donations; the less wealthy joined noble retinues.
At Constantinople, tensions with the Byzantines resulted in skirmishes. Emperor Alexios demanded oaths from the crusader leaders to return former Byzantine lands before allowing passage into Anatolia. The crusading host numbered 60,000–100,000, including 30,000 non-combatants and up to 7,000 knights. Exploiting Seljuk distractions, the crusaders and Byzantines captured Nicaea in June 1097 and advanced toward Antioch, once a Byzantine provincial capital in Syria. They repelled Kilij Arslan's lightly armoured cavalry at the Battle of Dorylaeum.