The Fourth Crusade and the Sack of Constantinople

I. Innocent III and the Call of 1198

Lothar of Segni was elected pope as Innocent III in January 1198 at the age of thirty-seven. He was the most powerful pope of the Middle Ages, a trained theologian and lawyer who believed that the pope was the vicar of Christ with authority over all Christians. The recovery of Jerusalem, lost to Saladin in 1187 and not regained by the Third Crusade, was one of his central aims. In August 1198 he issued the bull Post miserabile calling for a new crusade to set out in March 1199.

Innocent made two innovations. He insisted that the crusade should be under papal direction rather than that of kings, and he sought to pay for it by taxing the clergy. In 1199 he ordered all clergy to pay one fortieth of their revenues for the crusade, the first general papal tax on the church. He also extended the indulgence to those who sent a substitute or contributed money, a measure that would later be much abused.

The kings of the west were in no position to respond. Richard I of England was at war with Philip II of France and died in April 1199. The German throne was disputed between Philip of Swabia and Otto of Brunswick. The response came instead from the nobility of northern France and the Low Countries. In November 1199, at a tournament at Écry in Champagne, Count Thibaut of Champagne and Count Louis of Blois took the cross, followed in 1200 by Count Baldwin of Flanders and Hainaut. The preacher Fulk of Neuilly had already been active in raising enthusiasm.

II. The Treaty of Venice

The leaders decided to go by sea and to attack Egypt, which had become the centre of Ayyubid power and the key to Jerusalem. In 1201 six envoys, among them Geoffrey of Villehardouin, marshal of Champagne, went to Venice to negotiate transport. The doge, Enrico Dandolo, was about ninety years old and blind or nearly blind, but he was a shrewd and energetic ruler.

The treaty agreed in April 1201 provided for Venice to transport and supply 4,500 knights with their horses, 9,000 squires and 20,000 foot soldiers for a year, for the sum of 85,000 marks of silver. Venice would also contribute fifty armed galleys in return for half of all conquests. The destination was kept secret, but it was understood to be Egypt. Venice had to suspend most of its commercial activity for a year and a half to build and fit out the fleet, an enormous investment.

The fatal flaw of the treaty was the estimate of numbers. The envoys had no way of knowing how many crusaders would come, and the figure of 33,500 proved far too high. Many crusaders made their own arrangements and sailed from other ports, such as Marseilles and Apulia. Thibaut of Champagne, the chosen leader, died in May 1201, and the command passed to Boniface, marquis of Montferrat, a north Italian noble with family connections to the Byzantine court and to the crusader states.

III. The Debt and the Diversion to Zara

When the crusaders assembled at Venice in the summer of 1202, there were only about 12,000 of them, and they could pay only 51,000 marks of the 85,000 owed. They were encamped on the island of the Lido, dependent on the Venetians for food. Dandolo proposed a solution. The debt would be deferred if the crusaders helped Venice recover the city of Zara on the Dalmatian coast, which had rebelled against Venice in 1181 and placed itself under the king of Hungary.

The proposal was deeply troubling. Zara was a Christian city, and King Emeric of Hungary had himself taken the cross. Innocent III, informed of the plan, forbade the crusaders to attack any Christians. But the leaders felt they had no choice. In a ceremony in St Mark's, Dandolo himself took the cross, and many Venetians followed him. The fleet sailed in October 1202.

Zara was besieged from 10 November. The citizens hung crosses from the walls in the hope of averting an attack by crusaders. Abbot Guy of Vaux-de-Cernay, a Cistercian, read out a letter from the pope forbidding the attack, and Simon de Montfort, the future leader of the Albigensian Crusade, withdrew his men. But the city fell on 24 November and was sacked. Innocent excommunicated the whole army, though he later lifted the sentence on the crusaders while leaving it on the Venetians.

IV. The Young Alexios

During the winter at Zara envoys arrived from Philip of Swabia, king of Germany, on behalf of his brother-in-law, Alexios Angelos. Alexios was the son of the Byzantine emperor Isaac II, who had been deposed and blinded by his own brother, Alexios III, in 1195. The young Alexios had escaped to the west and sought help to restore his father.

The offer he made was extraordinary. If the crusaders restored Isaac and himself to the throne, he would pay them 200,000 marks of silver, provide supplies for the whole army for a year, send 10,000 Byzantine troops on the crusade to Egypt, maintain 500 knights in the Holy Land for the rest of his life, and place the Greek church under the authority of Rome. Boniface of Montferrat, who had met Alexios at Philip's court, supported the proposal, and so did Dandolo, since it promised the payment of the debt.

The army was bitterly divided. Many crusaders, including a group of Cistercian abbots, believed that the diversion was a betrayal of their vow. Some left and made their way to Syria independently. The majority, however, accepted the argument of Villehardouin and the leaders that without money and supplies the crusade could achieve nothing, and that the reunion of the churches would be a great service to God. The agreement was concluded in April 1203.

V. The Question of Intent

Historians have long debated whether the diversion to Constantinople was planned from the beginning. In the nineteenth century some argued that Venice had deliberately diverted the crusade to protect its trade with Egypt, or that Philip of Swabia and Boniface had conspired to seize the Byzantine throne. These theories have largely been abandoned. Most historians now follow Donald Queller and Thomas Madden in seeing the diversion as the result of a series of decisions, each of which seemed reasonable at the time, made by leaders trapped by the debt to Venice.

This view has been challenged by those who emphasise the long history of western hostility to Byzantium, the ambitions of the Normans, the Venetians and the Hohenstaufen against the empire, and the resentment caused by the Byzantine treatment of earlier crusades and by the massacre of the Latins of Constantinople in 1182, when thousands of Italian merchants and their families had been killed by a mob. Whatever the intentions of the leaders, these memories made the decision to attack Constantinople easier to accept.

VI. The First Siege of Constantinople

The fleet arrived off Constantinople in June 1203. It was the largest city in Christendom, with perhaps 400,000 inhabitants, protected by the great land walls of Theodosius II and by sea walls along the Bosphorus, the Golden Horn and the Sea of Marmara. The crusaders were astonished by its size and wealth. Villehardouin wrote that no one could have believed there was so rich a city in all the world.

The crusaders had expected the people to welcome the young Alexios. When he was paraded beneath the walls, they were met with indifference or hostility. On 5 July the army landed at Galata, broke the chain that closed the Golden Horn, and the fleet entered the harbour. On 17 July the crusaders attacked the land walls near the Blachernae palace, while the Venetians attacked the sea walls along the Golden Horn. Dandolo, standing in the bow of his galley with the banner of St Mark, ordered his men to put him ashore, and the Venetians took a stretch of the walls and set fire to the neighbouring quarter.

That night Alexios III fled the city with his daughter and a quantity of treasure. The Byzantine officials released Isaac II from prison and restored him to the throne, and the young Alexios was crowned co-emperor as Alexios IV on 1 August 1203.

VII. The Failure of Alexios IV

Alexios IV could not keep his promises. The treasury was empty, and he resorted to melting down church plate and icons, which outraged the clergy and people. His submission of the Greek church to Rome was hated. The crusaders, camped outside the city at Galata, grew impatient for payment, and they accompanied Alexios on an expedition in Thrace to secure his authority against his uncle's supporters.

In August 1203 a group of crusaders attacked a mosque in the city, which served the Muslim merchant community, and started a fire that burned for several days and destroyed a large part of the city's centre. Thousands of Latin residents fled to the crusader camp. Relations between the citizens and the crusaders collapsed. By November Alexios had stopped paying, and in December he broke openly with the crusaders, who demanded payment in a defiant embassy. The Byzantines tried twice to burn the Venetian fleet with fire ships.

In late January 1204 a palace revolt led by the official Alexios Doukas, known as Mourtzouphlos from his heavy eyebrows, overthrew Alexios IV. Mourtzouphlos had him strangled in prison in February, and Isaac II died at about the same time. Mourtzouphlos was crowned as Alexios V and prepared to resist the crusaders.

VIII. The Decision to Conquer

With the death of Alexios IV, the crusaders had no Byzantine ally and no hope of payment. They decided to take the city for themselves. In March 1204 the leaders made a treaty dividing the expected conquests. A committee of six Venetians and six crusaders would elect a Latin emperor, who would receive a quarter of the empire, including two palaces in the capital, while the remaining three quarters would be divided equally between Venice and the crusaders. The party that did not provide the emperor would choose the patriarch.

The clergy in the army assured the crusaders that the war was just. They argued that the Greeks were schismatics who had rejected the authority of the pope, and that the murder of Alexios IV made them guilty of treason. They promised the same indulgence as for the crusade against the Muslims to those who died in the attack. Innocent III was not consulted, and he had already warned the army not to attack the Greeks unless they obstructed the crusade.

IX. The Assault and the Sack

The first assault on 9 April 1204, against the sea walls of the Golden Horn, was repulsed with heavy losses. On 12 April the fleet attacked again, with ships lashed together in pairs to carry flying bridges to the tops of the towers. A north wind drove the ships against the walls. Two ships, the Pilgrim and the Paradise, carrying the bishops of Soissons and Troyes, reached a tower, and a Venetian and a French knight crossed onto it. At the same time a group under Peter of Amiens broke through a postern gate. Mourtzouphlos fled in the night.

On 13 April the crusaders entered the city, and for three days they plundered it. The Byzantine historian Niketas Choniates, who lived through the sack and escaped with his family with the help of a Venetian friend, described it in his history. The crusaders broke into churches, stripped the altars, smashed icons and carried off relics and plate. In Hagia Sophia, according to Choniates, they used mules to carry away the treasure, and a prostitute sat on the patriarch's throne and sang bawdy songs. Nuns were raped and citizens killed. Choniates wrote that even the Saracens had been merciful compared with these men who bore the cross of Christ on their shoulders.

The western accounts are less detailed but confirm the scale. Villehardouin said that never since the creation of the world had so much booty been taken in a city. The leaders had ordered that all plunder should be gathered and divided, and some looters were hanged, but much was concealed. The total value of the booty that was declared was about 900,000 marks.

X. The Theft of Relics

Constantinople possessed the greatest collection of relics in Christendom, including fragments of the cross, the crown of thorns, the lance and the burial cloth of Jesus, and the bodies or heads of many saints. Many of these were carried to the west in 1204 and the following years. The monk Gunther of Pairis wrote an account of how his abbot, Martin, forced a Greek priest at the point of a sword to show him the hidden relics of a monastery, and carried them back to Alsace, describing the theft as a holy robbery.

The relics were distributed to churches throughout France, Germany and Italy, and they gave rise to new cults and new reliquaries. The four bronze horses that now stand in St Mark's in Venice were taken from the Hippodrome. The crown of thorns was pawned by the Latin emperor Baldwin II to Venetian merchants and redeemed by Louis IX of France, who built the Sainte-Chapelle in Paris to house it.

The trade in relics shows how far the crusade had moved from the faith of the Scriptures. The apostle Paul told the Athenians that God does not dwell in handmade temples (Acts 17:24-25), and Jesus taught that the true worshippers would worship in spirit and truth (John 4:23-24). The veneration of objects associated with Jesus or the saints, and the willingness to steal them by violence, have no foundation in the teaching of the Greek Scriptures.

XI. Libraries and Manuscripts

The sack of 1204 also destroyed manuscripts and works of art. Constantinople was the principal centre for the copying of Greek texts, including the Greek Scriptures, the Septuagint and the works of classical antiquity. Many libraries were damaged in the fires of 1203 and 1204 and in the sack. The extent of the loss of literature is difficult to measure, but some classical works known to Byzantine scholars of the twelfth century do not survive after 1204.

Many Greek manuscripts of the Scriptures, however, survived in the monasteries of Mount Athos, Sinai and elsewhere, and the Greek tradition of copying resumed after the recovery of the city in 1261. The site's pages on Greek Bible Transmission and on the Greek Scriptures in Byzantium describe how the text was preserved through these upheavals. The sack also had an unintended effect, since some Greek manuscripts were carried west and contributed in time to the revival of Greek learning in Italy.

XII. The Latin Empire of Constantinople

On 9 May 1204 the electors chose Baldwin of Flanders as emperor rather than Boniface of Montferrat. He was crowned in Hagia Sophia on 16 May. The Venetian Thomas Morosini became the first Latin patriarch. Boniface received the kingdom of Thessalonica. The crusaders then divided the remaining lands of the empire, much of which had not yet been conquered, among themselves, creating a patchwork of fiefs in Thrace and Greece, including the principality of Achaea in the Peloponnese and the duchy of Athens.

Venice took the most valuable territories for trade, including three eighths of Constantinople, the island of Crete, the ports of Modon and Coron in the Peloponnese, and many islands in the Aegean. Dandolo took the title of lord of a quarter and a half of a quarter of the Roman empire. He died in Constantinople in 1205 and was buried in Hagia Sophia.

The Latin Empire was weak from the beginning. In April 1205 Baldwin was defeated and captured by the Bulgarian tsar Kaloyan at Adrianople, and he died in captivity. His brother Henry, an able ruler, succeeded him and reached an accommodation with the Greek population, but after his death in 1216 the empire declined. The Greeks established successor states at Nicaea, Trebizond and Epirus. In 1261 the emperor of Nicaea, Michael VIII Palaiologos, recovered Constantinople, and the Latin Empire came to an end.

XIII. Innocent III's Response

Innocent III's reaction to the conquest was at first enthusiastic. He saw it as a judgement of God on the Greeks and as an opportunity to reunite the churches. He wrote that God had transferred the empire from the proud to the humble, from the disobedient to the obedient. But when he learned of the sack, he condemned it in severe terms. In a letter of 1205 to the papal legate he wrote that the Greek church would rightly detest the Latins as dogs, since they had shed Christian blood, violated women, including nuns, and plundered churches.

Innocent also rebuked the legate Peter Capuano for releasing the crusaders from their vow to go to the Holy Land. Few of them went on to Syria. The army that had been raised to recover Jerusalem never reached it. Innocent turned his energies to a new crusade, which resulted in the Fifth Crusade, and also to crusades within Christendom, against the Cathars of southern France.

XIV. The Breach between the Churches

The sack of Constantinople did more than any other event to make the separation of the Greek and Latin churches permanent. The mutual excommunications of 1054 had been an episode in a long estrangement, but many Greeks and Latins had continued to regard each other as members of the same church. After 1204, Latin bishops were installed in Greek sees, Greek clergy were required to swear obedience to Rome, and in some places Greek monasteries were given to Latin orders. The Greek population came to identify the Latin church with conquest.

Attempts at reunion were made at the Second Council of Lyons in 1274 and the Council of Florence in 1439, both under pressure of political necessity, and both were rejected by the Greek clergy and people. In 1453, as the Ottomans prepared to attack the city, the Byzantine grand duke Loukas Notaras is reported to have said that it would be better to see the Turkish turban in the city than the Latin mitre. In 2001 Pope John Paul II, visiting Athens, expressed regret for the sins of Latin Christians against the Orthodox, mentioning the sack of Constantinople. In 2004 he made a similar statement to the patriarch of Constantinople.

XV. The Jews of Constantinople

Constantinople had a Jewish community of about 2,500 according to Benjamin of Tudela, who visited about 1170, living in the quarter of Pera across the Golden Horn, and including both Rabbanite and Karaite Jews. Benjamin reported that they were hated by the Greeks and subject to restrictions. The community suffered in the fires and the sack, and in the Latin period the Jews were subject to Venetian and other Latin authorities. The site's page on the Romaniote Jews describes the Greek-speaking Jews of the Byzantine world.

XVI. Why the Crusade Went Astray

The Fourth Crusade raises with special clarity the question of how a religious enterprise can be turned to other ends. Its participants had taken a vow to fight for the recovery of Jerusalem, yet they ended by attacking two Christian cities. At each stage they were persuaded that the diversion would serve the ultimate goal, and at each stage they were further from it. Debt, the ambitions of individual leaders, the commercial interests of Venice and long-standing hostility to the Greeks combined to produce an outcome that almost no one had intended.

The Greek Scriptures warn of the danger of the love of money. Paul told Timothy that the love of money is a root of all sorts of injurious things, and that some, reaching out for it, have been led astray from the faith (1 Timothy 6:10). Jesus said that no one can slave for two masters, God and Riches (Matthew 6:24). The crusade's dependence on Venetian credit, and the leaders' anxiety to obtain payment, show how a religious enterprise financed by debt could be bent to commercial and political purposes.

XVII. The Memory of 1204

The Fourth Crusade has been remembered very differently in east and west. In Venice it was celebrated for centuries as a triumph, commemorated in the paintings of the Doge's Palace and in the treasures of St Mark's. In France the chronicle of Villehardouin became a classic of French prose. In the Greek world the sack was remembered as the great catastrophe of Byzantine history, the moment when the Latins revealed their true nature.

Modern historians, both western and Greek, have generally regarded the sack as a disaster. Steven Runciman wrote that there was never a greater crime against humanity than the Fourth Crusade. This judgement may be exaggerated, but it reflects the sense that the sack destroyed much of what was most valuable in the civilisation of Christendom, weakened the barrier that Byzantium had provided against the Turks, and made reconciliation between the churches almost impossible.

XVIII. Assessment

The Fourth Crusade never reached the Holy Land. It was raised to recover Jerusalem and ended by conquering Constantinople. It was the clearest demonstration of the dangers inherent in the idea of holy war, since an army that had been told that killing for the faith was meritorious could be turned against fellow Christians as easily as against Muslims. The clergy who accompanied the army used the same language of indulgence for the attack on Constantinople as for the war against the Muslims.

The crusade weakened Byzantium fatally, contributed to the eventual Ottoman conquest, and left a deep wound in relations between Greek and Latin Christians. It also showed the limits of papal authority, since Innocent III was unable to control an army that had been raised in his name. Jesus' words that his followers would be recognised by their love for one another (John 13:35) stand in stark contrast to the events of April 1204.

XIX. Venice and Byzantium before 1204

Venice had been a Byzantine dependency in its early history, and it retained close ties with Constantinople. In 1082 the emperor Alexios I Komnenos granted the Venetians sweeping trading privileges, including exemption from customs duties throughout most of the empire and a quarter of their own on the Golden Horn, in return for naval help against the Normans of southern Italy. The privileges made Venetian merchants wealthy and increasingly resented by the Greek population, whose own merchants paid duties from which the Venetians were exempt.

Relations deteriorated in the twelfth century. In 1171 the emperor Manuel I Komnenos ordered the arrest of all Venetians in the empire and the confiscation of their property, and thousands were imprisoned. Venice sent a fleet in retaliation, which was destroyed by disease. Enrico Dandolo himself had served as an envoy to Constantinople in these years, and a later tradition claimed that he had been blinded by the Greeks, though this is not supported by contemporary evidence. Relations were restored in the 1180s, but the memory of 1171 and 1182 made the Venetians distrustful of Byzantine promises.

XX. Robert of Clari and the View from the Ranks

Alongside Villehardouin, who wrote as one of the leaders and defended their decisions, the crusade is described by Robert of Clari, a poor knight from Picardy. Robert's account gives a vivid picture of the experience of ordinary crusaders. He describes the wonders of Constantinople, its palaces, churches and relics, with wide-eyed admiration, and he records the resentment of the rank and file at the way the leaders divided the booty, keeping the best for themselves.

Robert reports that the clergy preached before the final assault that the Greeks were worse than Jews, enemies of God, and that the war against them was righteous. His account shows how the language of holy war was used to justify the attack. It also shows that many crusaders did not understand the political calculations of the leaders and felt cheated by the outcome. His chronicle survives in a single manuscript now in Copenhagen.

XXI. The Greek Successor States

The conquest of 1204 did not destroy Byzantine political life. Theodore Laskaris, a son-in-law of Alexios III, established himself at Nicaea in Asia Minor and was crowned emperor in 1208 by a Greek patriarch elected in exile. The Komnenos family founded an empire at Trebizond on the Black Sea coast with Georgian help, which survived until 1461. Michael Komnenos Doukas created a state in Epirus in western Greece, whose rulers captured Thessalonica in 1224.

The Nicaean emperors, especially John III Vatatzes, rebuilt the economy and military strength of the Greek world and gradually recovered territory in Europe. Nicaea became a centre of Greek learning and of resistance to the Latin church, and its rulers saw themselves as the legitimate heirs of the Roman empire. In 1261 a Nicaean general, Alexios Strategopoulos, found Constantinople almost undefended while the Latin garrison was away and took it with a small force. The restored empire, however, was much weaker than before 1204 and never recovered its former strength.

XXII. Frankish Greece

The Latin conquests in Greece proved more durable than the empire itself. The principality of Achaea, founded by William of Champlitte and Geoffrey of Villehardouin, nephew of the chronicler, became a model of western feudal society, with castles, tournaments and a court that was praised as one of the most refined in Christendom. The Chronicle of Morea, written in Greek, French, Italian and Aragonese versions, records its history. The duchy of Athens passed in the fourteenth century to the Catalan Company and then to the Florentine Acciaiuoli family.

The Latin rulers generally tolerated the Greek church at the parish level while placing Latin bishops over it. Greek and Latin populations lived side by side, and in some places intermarried, but the division of the churches remained. Venetian Crete, held until 1669, saw repeated Greek revolts. The legacy of Frankish rule survives in the castles of the Peloponnese and the islands, and in the many Italian words in the Greek language.

XXIII. The Crusade and the Holy Land

The diversion of the crusade deprived the crusader states of reinforcements they badly needed. The kingdom of Jerusalem, now centred on Acre, had made a truce with the Ayyubids, and its rulers hoped for an army that could recover Jerusalem. Some crusaders who had refused to go to Constantinople did reach Syria, but they were too few to achieve anything, and many died of disease. Meanwhile, the Latin Empire drew settlers and knights who might otherwise have gone to the Holy Land, and the papacy diverted crusading resources to its defence. The conquest of Constantinople thus weakened rather than strengthened the Latin position in the east.

XXIV. The Hippodrome Bronzes

Among the casualties of the conquest were the great bronze statues of the city, many of them ancient works brought to Constantinople by Constantine and his successors. Niketas Choniates wrote a lament on the statues melted down by the Latins for coin, including a colossal Hera, a Herakles attributed to Lysippos, and figures of Paris and Helen. To Choniates, who had been educated in the classical tradition, their destruction was a sign of the barbarism of the conquerors, who valued the bronze only for its metal. The few bronzes that survived, like the horses of St Mark's, survived because they were carried off whole as trophies. The loss of these works, which had stood for nearly nine centuries, deprived later generations of some of the most famous sculptures of antiquity, known now only through descriptions.

XXV. A Note on Numbers

Medieval figures for armies, booty and populations must be treated with caution. The numbers given here for the crusading army, the population of Constantinople and the value of the plunder are drawn from contemporary chroniclers and the estimates of modern historians, and they should be read as approximate orders of magnitude rather than precise counts.

XXVI. Chronology

In 1182 the Latins of Constantinople were massacred. In 1195 Isaac II was deposed by Alexios III. In January 1198 Innocent III became pope, and in August 1198 he issued Post miserabile. In November 1199 Thibaut of Champagne took the cross at Écry. In April 1201 the Treaty of Venice was concluded, and in May 1201 Thibaut died. In the summer of 1202 the crusaders assembled at Venice, and on 24 November 1202 Zara fell. In April 1203 the agreement with the young Alexios was concluded.

On 24 June 1203 the fleet reached Constantinople. On 17 July 1203 the city was attacked and Alexios III fled, and on 1 August Alexios IV was crowned. In August 1203 a great fire destroyed much of the city. In late January 1204 Mourtzouphlos seized power, and in February Alexios IV was killed. In March 1204 the crusaders agreed to divide the empire. On 9 April an assault failed, and on 12 April 1204 the city fell. On 16 May 1204 Baldwin was crowned. In April 1205 Baldwin was captured at Adrianople. In 1261 Michael VIII recovered Constantinople.

XXVII. Bibliography

The following studies, editions and reference works underlie this account.