Battles & Wars › Medieval wars
The Crusades
1096–1291· War· Middle East & Africa
Well documentedSolid records, physical evidence or scientific consensus.
A series of Christian holy wars, called by the popes, to win and hold Jerusalem and the Holy Land from Muslim rulers.
See it on the Battles & Wars map →What happened
In 1095 Pope Urban II answered a Byzantine plea for help against the Seljuk Turks by calling Western Christians to free Jerusalem. The First Crusade took it in 1099 and set up four crusader states. Later crusades tried to defend or regain them: Saladin retook Jerusalem in 1187, the Fourth Crusade sacked Christian Constantinople in 1204, and the last major crusader stronghold, Acre, fell to the Mamluks of Egypt in 1291. Crusades were also waged in Spain, the Baltic and against heretics.
Why it matters
They deepened Christian–Muslim and Catholic–Orthodox hostility, fatally weakened Byzantium, boosted Italian trade with the East, and left the word 'crusade', still loaded today.
How we know
Abundant chronicles by Latin, Greek, Arabic and Armenian writers, papal letters, charters, and surviving castles such as Krak des Chevaliers.
Still debated
Historians debate the balance of motives: genuine piety, land and plunder, papal politics, or defense of Eastern Christians.
Inside this (5)
Connections (13)
▸The Crusades aimed to retake lands won in Early Muslim conquestsMostly agreed
The connection
Jerusalem and Syria had been Christian Roman lands until the conquests of the 630s. Pope Urban II framed the First Crusade as recovering them, while Byzantium hoped to regain Anatolia, lost more recently to the Seljuk Turks. By 1096 the Holy Land had been under Muslim rule for more than four centuries.
When and how
Conquests in the 630s; crusades from 1096, after Pope Urban II's call at Clermont, France, in November 1095.
How sure are we?
Reports of Urban's sermon and crusaders' letters speak of liberating Jerusalem and Eastern Christians.
Debates and open questions
Whether the Crusades were a delayed response to Islamic expansion, as some argue, or mainly a product of 11th-century European conditions is debated.
▸Stirrup and heavy cavalry (knights) spearheaded The CrusadesWell documented
The connection
Western knights charging in close order with couched lances were the crusaders' shock weapon; the Byzantine princess Anna Komnene wrote that their charge could pierce the walls of Babylon. Muslim armies, built around lighter horse archers, learned to avoid the charge and wear knights down. The Templars and Hospitallers became standing orders of knights.
When and how
Anatolia and the Holy Land, 1096–1291; Frankish knights and the military orders, the Templars founded about 1119.
How we know
Crusader, Byzantine and Arab writers all describe the Frankish charge, including Anna Komnene's Alexiad and Usama ibn Munqidh's memoirs.
Debates and open questions
How much crusader success came from the charge versus Muslim disunity is debated.
▸The Crusades won their greatest prize at Siege of Jerusalem (1099)Well documented
The connection
Jerusalem was the stated goal of the First Crusade. Its capture seemed miraculous to crusaders after three years of marching, famine and the long siege of Antioch, and it was the only time crusaders took the city by force. It created the Kingdom of Jerusalem and inspired later crusades to defend or regain it.
When and how
Jerusalem, June 7 to July 15, 1099; leaders included Godfrey of Bouillon, Raymond of Toulouse and Tancred.
How we know
Several eyewitness chronicles describe the march and siege, and crusade leaders' letters home report the capture.
Debates and open questions
Why such a depleted army succeeded is debated: Fatimid weakness, Genoese engineering help, or rivalry among Muslim powers.
▸Battle of Hattin provoked a new wave of The CrusadesWell documented
The connection
At Hattin, Saladin destroyed the field army of the crusader Kingdom of Jerusalem, leaving its towns nearly undefended. Jerusalem surrendered on October 2, 1187. The shock in Europe launched the Third Crusade (1189–92) under Richard I of England, Philip II of France and Emperor Frederick Barbarossa. It regained coastal cities such as Acre, but not Jerusalem.
When and how
Galilee, July 4, 1187, then Jerusalem, October 1187; Pope Gregory VIII called the new crusade that same month.
How we know
Gregory VIII's crusade appeal, Audita tremendi (October 1187), cites the disaster in the Holy Land and the loss of the True Cross relic.
Debates and open questions
Whether the battle or the fall of Jerusalem moved Europe more is a matter of emphasis; royal rivalries also drove the Third Crusade.
▸Castles and siege warfare anchored the crusader states during The CrusadesWell documented
The connection
The crusader states never had enough knights to hold open country, so they relied on castles. Great fortresses like Krak des Chevaliers, held by the Hospitallers, guarded roads and borders with small garrisons. After the disaster at Hattin, fortified coastal cities, first Tyre and, from 1191, Acre, let the crusaders hang on for another century.
When and how
Today's Syria, Lebanon, Israel, Palestine and Jordan, 1099–1291; builders included the kings of Jerusalem and the military orders.
How we know
Ruins survive across the region; chronicles and charters record their building, garrisons and sieges by Saladin and the Mamluks.
Debates and open questions
How far crusader castle design copied Byzantine and Islamic models, or shaped castles back in Europe, is debated.
▸The Crusades weakened Byzantium long before Fall of ConstantinopleMostly agreed
The connection
The Fourth Crusade, diverted by debts to Venice and a Byzantine succession quarrel, captured and sacked Constantinople in 1204 and set up a Latin empire there. The Byzantines retook the city in 1261, but the empire never recovered its wealth, territory or navy. Shrunken and poor, it could not stop the rising Ottomans, who took it in 1453.
When and how
Constantinople, April 1204; crusaders and Venetians under Doge Enrico Dandolo and Boniface of Montferrat; Latin rule lasted until 1261.
How sure are we?
Eyewitnesses Geoffrey of Villehardouin, Robert de Clari and the Byzantine Niketas Choniates describe the sack; the bronze horses of St Mark's in Venice were part of the loot.
Debates and open questions
Historians debate how much 1204, rather than later civil wars, plague and Ottoman strength, explains the fall of 1453.
▸Saladin (Salah al-Din) united Egypt and Syria to fight The CrusadesWell documented
The connection
The crusader states survived partly because Muslim Egypt and Syria were divided. Saladin, after taking power in Egypt in 1169 and Damascus in 1174, spent a decade bringing Syria and northern Iraq under his rule, encircling the crusaders. His victories triggered the Third Crusade, which he fought to a draw, keeping Jerusalem.
When and how
Egypt, Syria and the Levant, 1169–1192; the Third Crusade of 1189–1192 against Richard I of England and Philip II of France.
How we know
His biographers and Latin chronicles document his campaigns; the 1192 Treaty of Jaffa ended the Third Crusade.
Debates and open questions
Historians debate whether his years of fighting fellow Muslims served holy war against the crusaders or mainly his family's power.
▸Wars of the Hebrew Bible supplied holy-war ideas invoked in The CrusadesDebated
The connection
Medieval preachers and chroniclers cast crusaders as a new Israel reclaiming a promised land. They quoted Joshua, Judges and the Psalms, and called the capture of Jerusalem in 1099 God's work. Christian holy-war ideas also drew on Augustine's 'just war' theory and church reform.
When and how
Pope Urban II preached the First Crusade at Clermont in 1095; chroniclers such as Robert the Monk and Raymond of Aguilers used Old Testament language.
How sure are we?
Crusade sermons, letters and chronicles explicitly cite Old Testament wars and call crusaders new Israelites or new Maccabees.
Debates and open questions
Historians debate how much the Bible itself drove crusading, compared with papal politics, the promise of forgiveness for sins, land and plunder.
▸Battle of Manzikert prompted the Byzantine appeal behind The CrusadesWell documented
The connection
After Manzikert, Turkish groups took most of Anatolia, reaching Nicaea, close to Constantinople. Emperor Alexios I Komnenos sent envoys to Pope Urban II in 1095 asking for Western soldiers. Urban answered at Clermont that November by calling for an armed pilgrimage to Jerusalem, which became the First Crusade.
When and how
Anatolia after 1071; Council of Piacenza, March 1095, and Council of Clermont in France, November 1095; Alexios I and Urban II.
How we know
Western chroniclers record Byzantine envoys at Piacenza, and Alexios's daughter Anna Komnene wrote about the Turkish threat and the crusaders' arrival.
Debates and open questions
Alexios likely wanted mercenaries, not a mass movement aimed at Jerusalem; how much Urban's call was about helping Byzantium versus papal and religious aims is debated.
▸Battle of Grunwald (Tannenberg) crippled the Teutonic Order, heirs of The CrusadesWell documented
The connection
The Teutonic Order was founded at Acre in 1190 during the Third Crusade, then moved to the Baltic, where it crusaded against pagan Prussians and Lithuanians and built its own state. Lithuania's conversion in 1387 had already weakened its purpose. Grunwald killed its grand master and much of its leadership, and the Order never fully recovered.
When and how
Order founded at Acre, 1190; Baltic crusades from the 1230s; Grunwald, Prussia (now northern Poland), July 15, 1410.
How we know
The Order's own records and papal documents trace its line from the Holy Land to Prussia; both sides recorded its losses at Grunwald.
Debates and open questions
Historians debate whether the Order's decline came mainly from the battle or from the war debts, heavy taxes and Prussian revolt that followed.
▸Trebuchet (traction and counterweight) battered city walls during The CrusadesWell documented
The connection
Crusader and Muslim armies both relied on trebuchets in the many sieges of the Crusades, from Nicaea and Antioch to Acre. Muslim engineers, such as those writing for Saladin, described powerful counterweight machines. At Acre in 1291 the Mamluks reportedly brought dozens of engines, helping take the last major crusader stronghold.
When and how
The Levant, Anatolia and Egypt, 1097–1291; crusader, Byzantine, Ayyubid and Mamluk engineers.
How we know
Chroniclers on both sides describe trebuchets in sieges, and al-Tarsusi's treatise written for Saladin details their design.
Debates and open questions
Whether the counterweight trebuchet was invented by Byzantines, Muslims or crusaders during these wars is still argued.
▸Wootz crucible steel and Damascus blades gave famed 'Damascus' blades to Muslim armies of The CrusadesMostly agreed
The connection
Crusaders met Muslim armies carrying fine swords, some made of crucible steel and forged in Syria and Persia. Over time 'Damascus' blades gained a near-mythical reputation in Europe. Good Western swords were often comparable in practice, but the mystique of the Eastern blade stuck.
When and how
The Levant, 1096–1291; blades linked to the markets and workshops of Damascus.
How sure are we?
Arabic sword treatises and surviving later blades confirm crucible-steel swords; blades surely from the crusade era are rare, so the link rests partly on later accounts.
Debates and open questions
Famous tales, such as Saladin slicing a floating silk scarf, come from Walter Scott's 1825 novel; how common such blades were in crusade-era armies is unknown.
▸Venetian Arsenal built ships for Venice's role in The CrusadesMostly agreed
The connection
Venice supplied ships, transport and supplies to crusaders and won trading quarters in the Levant in return. Its biggest role came in the Fourth Crusade: in 1201 it contracted to ship about 33,500 crusaders. When they could not pay, the expedition was diverted, ending in the sack of Constantinople in 1204.
When and how
Venice and the eastern Mediterranean, 1100s–1200s; Doge Enrico Dandolo led the Fourth Crusade fleet in 1202–1204.
How sure are we?
The 1201 Treaty of Venice and chroniclers such as Geoffrey of Villehardouin record the contract and the fleet.
Debates and open questions
The early Arsenal was small; how much of the crusade fleets it built, versus private Venetian shipyards, is uncertain.