Decline of an Empire: The Fourth Crusade’s Sacking of Constantinople


The Byzantine Empire, heir to the Roman Empire, the Republic before them, and the Hellenic Kingdoms before them, fell for good in 1453. In 1204, however, the city suffered a crippling sacking that forever broke the back of the Empire.

A result of the disastrous Fourth Crusade, Constantinople found itself looted by the very Crusaders supposedly sent to help it. The story behind the betrayal fittingly reads like a Greek tragedy, with a hint of old Roman satire thrown in for good measure.

Boniface elected as leader of the Fourth Crusade, Soissons, 1201: history painting by Henri Decaisne, early 1840s.

In March of 1199, Pope Innocent III declared the Fourth Crusade. The Crusade was intended, like most such crusades, to recapture Jerusalem. Unlike the First Crusade, the Byzantine Emperor had not beseeched the Pope for help. Instead, this crusade was the idea of the Pope himself, its formation and success a driving force of his pontificate.

Unfortunately for the eager Pope, none of the European nations had any interest in a crusade at that time. Too busy warring with each other or disgruntled with Papal authority, it was not until a wandering priest named Fulk of Neuily managed to rally people to the crusading banner.

Pope Innocent III

French knights gathered for a tournament formed the bulk of the crusade at first, though others slowly signed on for the crusade, among them several French nobles and even nobles from Flanders. Having amassed their crusading army, the Crusade now faced the logistical problem of getting to the Holy Land. The most powerful naval force in the Mediterranean was Venice, so they were the natural choice to ferry the Crusaders to Jerusalem.

Venetian Galley (14th century)

The crusaders sent envoys to speak with the leader of Venice, Doge Enrico Dandalo, in 1201. The Doge received the envoys well; Venice held a history of crusading in some form or another over the years.  However, despite the extent of Venice’s trade, even Doge Dandalo was taken aback by the size of the fleet needed for the crusade –anticipating a large Crusade, the envoys requested a large fleet to ferry them to their destination.

Dandolo Preaching the Crusade by Gustave Doré

The Venetian Senate and Doge spent several weeks discussing the Crusaders request. Eventually the Venetian government agreed to aid the Crusade, though not without some conditions. As the Doge explained, “We will build transports to carry four thousand five hundred horses, and nine thousand squires, and ships for four thousand five hundred knights, and twenty thousand sergeants of foot.

And we will agree also to purvey food for these horses and people during nine months. This is what we undertake to do at the least, on condition that you pay us for each horse four marks, and for each man two marks.”

The siege of Constantinople in 1204, by Palma il Giovane

All told, The Venetian government asked for 85,000 marks of silver to offset the cost of transporting the Crusaders. The Crusaders accepted Venice’s fee, and in 1201 they and Venice signed an agreement known as the Treaty of Venice.

The leader of the Crusade, Boniface, The Marquis of Montferrat, made possible the first interaction between the Crusaders and the Byzantine Empire. On his way to join the Crusade, Boniface met Prince Alexius, the son of the deposed Emperor Isaac II Angelus of the Byzantine Empire. Eager to depose his uncle, Emperor Alexius III, who took over the thrown from his father, Prince Alexius, in true Byzantine fashion, plotted with Boniface on the way to Venice.

Miniature of Emperor Alexios III Angelos in Biblioteca Estense of Modena

The Prince’s plan was simple; the Crusading Army would show up at the walls of Constantinople, and the city, cowed by the show of force, would welcome the wayward Prince without bloodshed. The plan had precedent, and intrigued the Crusading nobles, though for the time they declined, not wanting to involve themselves in Byzantine politics on top of the logistical issues of a Crusade.

Topographical map of Constantinople during the Byzantine period

Said logistical issues only increased when the Crusaders learned a hard lesson in economics. The Venetian’s fee was set, and, unfortunately for the Crusaders, they lacked the number of men stipulated in the agreement.

As Geoffroi de Villehardouin, a historian and knight participating in the Crusade wrote, “The cost of each man’s passage was now levied throughout the host; and there were people enough who said they could not pay for their passage, and the barons took from them such moneys as they had.

So each man paid what he could. When the barons had thus claimed the cost of the passages, and when the payments had been collected, the moneys came to less than the sum due-yea, by more than one half.”

The Theodosian Walls in Constantinople. Gate of Springs(Silivri).

Fortunately for the cash strapped Crusaders, the Venetians had a solution to their limited funds. The outstanding amount would be suspended if the Crusaders helped the Venetians attack the city of Zara and pay the outstanding amount with plunder.

Under the realm of the king of Hungary, Zara was a Christian nation nominally under the Byzantine sphere of influence, as most of the former Balkan nations were part of the Empire before revolting and achieving their own independence.

Pope Innocent III vehemently opposed the attack –Crusades were for fighting heathens, not fellow Christians. The Crusaders, strapped for cash and facing autumn and the end of the sailing season, believed they had no choice but to accept the agreement. Per the agreement, the Venetians and their Doge joined the Crusade, much to the Crusaders consternation.

Constantinople in Byzantine times

Loaded onto the waiting ships, the Crusade sailed for Zara, a port city on the Mediterranean coast. In a combined amphibious assault and siege, the Crusaders captured the city on November 24, 1202. Throughout the siege the city hung crosses from its bastions to demonstrate its status as a Christian city, and several of the Crusading nobles, including Robert de Boves and Guy of Vaux-de-Cernay, refused to take part in the siege.

The Pope, incensed at the assault on a Christian settlement by the Crusaders, excommunicated the entire Crusade the following year. The Crusade pressed on, however, once again receiving Prince Alexius and his German cousin. The Prince came with an enticing offer, which, if the Crusaders accepted, would include German support of the Crusade.

Villehardouin explained that “if God grant that you restore him (the former emperor) to his inheritance, he will place the whole empire of Roumania (Byzantine Empire) in obedience to Rome, from which it has long been separated.

Further, he knows that you have spent of your substance, and that you are poor, and he will give you 200,000 marks of silver, and food for all those of the host, both small and great. And he, of his own person, will go with you into the land of Babylon, or, if you hold that that will be better, send thither 10,000 men, at his own charges.”

Map of Constantinople (1422) by Florentine cartographer Cristoforo Buondelmonti

Now fully embroiled in Venetian dealings and Byzantine politics, the horribly side-tracked –but still cash strapped- Crusade set sail for Constantinople on May 24, 1203. Emperor Alexius III, well aware of the intentions of the crusaders, prepared to defend the city rather than surrender.

On June 23 the fleet landed at the abbey of St. Stephen, and the Crusaders finally set their eyes on Constantinople, gateway to the Holy Land and capitol of the Byzantine Empire.

Conquest of Constantinople by the Crusaders in 1204

Despite his earlier determination, at the sight of the Crusaders besieging the capital, the Emperor fled, and on August 1 of 1203 Prince Alexius was crowned Emperor Alexius IV in his deposed father’s stead.

As per his agreement with the Crusaders, the new Emperor was expected, as Patriarch of the Orthodox Church, to submit to Rome and reunite the churches. The Emperor refused to do so, however, and, relations already strained between the Empire and the Crusaders, boiled over into full-on war.

The Horses of Saint Mark displayed on the facade of St Mark’s Basilica in Venice. Photo: Nino Barbieri / CC-BY-SA 2.5

As the Crusaders went to war the Emperor was murdered and replaced, and the Crusade paused to consider whether they would continue on to the Holy Land or settle things with the Empire. The Venetians settled the matter for the Crusade, and in the spring of 1204 the Crusade besieged Constantinople.

Assaulting the city twice, causing several fires in the process, the Crusaders managed, according to Villehardouin to gain a foothold in the city thanks to “a wind called Boreas which drove the ships and vessels further up on to the shore.

And two ships that were bound together, of which the one was called the Pilgrim and the other the Paradise, approached so near to a tower, the one on the one side and the other on the other-so as God and the wind drove them-that the ladder of the Pilgrim joined on to the tower. Immediately a Venetian, and a knight of France, whose name was Andrew of Urboise, entered into the tower, and other people began to enter after them, and those in the tower were discomfited and fled.”

The partition of the empire following the Fourth Crusade, c. 1204. Image: Justinian43 / CC-BY-SA 3.0

Following this foothold the new Emperor fled the city, and Constantinople surrendered in April of 1204. Though the civilian populace was spared, the city was thoroughly sacked Villehardouin could not account for the vast wealth. The mighty city of Constantinople, legacy of the Roman Empire, had fallen to the greed and ambitions of the Fourth Crusade, and the Byzantine Empire would never recover.

Works Cited:
Geoffrey de Villehardouin, Geoffrey de, Chronicle of The Fourth Crusade and The Conquest of Constantinople, trans. Frank T. Marzials, (London: J.M. Dent, 1908)
Phillips, Jonathon, Fourth Crusade and the Sack of Constantinople, (New York: Viking Press, 2004)