Today in European history: the Fourth Crusade sacks Constantinople (1204)

Crusaders, accompanied by their Venetian collaborators, take a fateful detour into Greece and temporarily topple the Byzantine Empire.

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The Fourth Crusade is for me, in many ways, the Crusadiest of all the Crusades. Sure, the First Crusade actually achieved its goal, which you can’t really say about any of the others in any serious sense, and other Crusades produced quintessential heroes like Richard the Lionheart and Saint Louis. But overall the Crusades were, and again this is just my own view, an enterprise that was marked more by petty infighting, poor planning, and a tendency to shoot (or stab) oneself in the foot than by dashing heroes or the triumphant “recovery” of the Holy Land for Christ. And the Fourth Crusade has more of that first list of stuff than any of the others. Any major military campaign that sets out to battle Muslims in the Levant and instead brings down the longest-lived Christian empire in the world, in Greece, is worth special consideration in my book.

Speaking of books, this epic flame-out and its geopolitical repercussions have probably generated more focused scholarship than any of the other Crusades, with only the First Crusade and the romantic Saladin-Richard the Lionheart conflict of the Third Crusade as possible rivals. There are several, but I particularly appreciate Michael Angold’s The Fourth Crusade and much of this entry is based on that book.

This very helpful map shows the route of the Crusade, which you’ll note comes nowhere near the Holy Land, along with the states that temporarily succeeded the Byzantine Empire (Kandi via Wikimedia Commons)

This is a very long post so we’ll break it up into sections.

The Players

There are three main players in this amazing story: the Byzantines, the Crusaders, and the Venetians. Some background on each is in order, but let’s start with the Byzantines because their political dysfunction is the biggest single factor in what transpired. Had the empire not been at one of the lowest ebbs in its history there is virtually no chance that a relatively ragtag Crusader-Venetian army could have knocked off one of the most impregnable cities in the world. Byzantine politics had been coming apart since at least the Battle of Manzikert in 1071, if not before. The collapse of the Macedonian Dynasty in the first half of the 11th century began a period of scheming and turmoil in the palace and that, combined with the devastating effects of the Turkish victory at Manzikert, upended what had been a relatively stable equilibrium between the royal family and key nobility.

The Komnenian dynasty, which ruled the empire from 1081 through 1185, restored some degree of political stability in Constantinople but it did so by trying to turn imperial governance into the family business. This was fine as far as it went, but it had the obvious effect of alienating parts of a nobility that by this point had come to view scheming for the throne as part of the normal course of doing business. When Manuel I Komnenos died in 1180 and was succeeded by his 11 year old son, Alexios II, the nobility went to work. First it replaced Alexios with his much older cousin, Andronikos I, in 1183, and then it brought the Komnenoi to an end entirely with the elevation of Isaac II Angelos as emperor in 1185.

Isaac tried to strengthen his position after taking the throne but the reality was his claim on royal authority was weak, his administration unpopular with much of the nobility, and his military record poor. The combination left him vulnerable to yet more palace scheming, and he was overthrown and blinded by his brother, Alexios III Angelos, in 1195. Blind but still alive, Isaac and his son, also named Alexios, spent the next few years actively pursuing a way back into power. They eventually settled on the Crusaders, but we’ll get to that. The upshot is that the Byzantine Empire at the turn of the 13th century was a hot mess. Comity between the royals and nobles had broken down and the empire was in the middle of being ruled by a series of weak usurpers with dubious claims to the throne. In addition to causing a crisis of legitimacy, all that usurpation didn’t leave much time for, say, investing in the military, particularly when the military could very well be harboring the next usurper.

Let’s turn to our second player here: the Crusaders. Obviously, Pope Innocent III (d. 1216) envisioned this Crusade going much differently when he proclaimed it in 1198. But things got off to a lousy start when the expedition’s obvious leader, the aforementioned Richard, died in 1199 while fighting to regain his holdings in France. Richard ended the Third Crusade having failed to retake Jerusalem, but he did win a pledge from his rival, Saladin, to leave Outremer alone for at least three years. He also ended the campaign with an insight: Jerusalem, and really the entire Crusading enterprise, would never be entirely secure without the conquest of Egypt. Saladin’s conquest of Jerusalem in 1187 and Richard’s experience on the subsequent Third Crusade had made it clear to him that Outremer couldn’t be sustained by irregular arrivals of reinforcements and material aid from Europe. The Crusader kingdoms needed their own source of wealth to support their own standing army.

Egypt offered that wealth, and it seemed ripe for the taking. Richard, with a hobbled and relatively small army, had dealt Saladin a series of defeats during the Third Crusade and believed that his army, while insufficient to besiege Jerusalem, could have successfully invaded Egypt at that time. Now Saladin was dead and had apportioned his realm among his sons and brothers—which, of course, meant civil war. So, like I said, ripe for the taking. When Innocent called a new Crusade, the senior nobles who responded settled on two things: one, that they would be led by Theobald III, the Count of Champagne, and two, that their target would be Egypt, not Jerusalem. Of course this raised an immediate problem—Crusading was inextricably linked with Jerusalem and indeed was sold to potential recruits as a martial pilgrimage to the holiest city in the Christian faith. Would it be possibly to generate the same religious zeal as past Crusades had generated for an invasion of Egypt? The Crusade’s leadership seem to have decided to sidestep this problem by simply not telling most of the rank and file where they were going and letting them assume that they would be going to Jerusalem.

Theobald’s unexpected death in 1201 (he was just 22 years old) disrupted the Crusade but only briefly. A new leader was identified in the person of Boniface I, Marquis of Montferrat (d. 1207). His older brother, Conrad of Montferrat, had once been married to Emperor Isaac’s sister and had defended the emperor against a revolt led by Byzantine general Alexios Branas. He’d then gone on to be elected King of Jerusalem until, um, some unpleasantness prevented him from actually taking the throne. With his family ties to both the empire and the Jerusalem crown (for which he almost certainly harbored some ambition), Boniface should have made an ideal leader for the new expedition. Instead his selection probably helped ensure that the effort would wind up going off the rails.

The Plot?

Boniface was a client of his very powerful cousin, Philip of Swabia, a son of former Holy Roman Emperor Frederick I Barbarossa and one of two contenders for the imperial throne alongside future Emperor Otto IV. You may recall Frederick for his initial participation in the Third Crusade, right up to his drowning in the Saleph River in 1190. His overall experience in that campaign, even leaving aside the whole death thing, was mostly negative and his unpleasant impression of the Byzantines had apparently been passed on to his sons. Philip’s brother, former Holy Roman Emperor Henry VI, had threatened to invade the Byzantine Empire to restore the deposed Isaac Angelos and Philip himself was married to none other than Irene Angelina, Isaac’s daughter. After Boniface was commissioned as the new leader of the forthcoming Crusade he spent Christmas 1201 at Philip’s court in Swabia, hanging out with Philip, Irene, and another special guest—Alexios Angelos, Isaac’s son and would-be Byzantine Emperor. It seems he and Isaac had paid a couple of merchants to get him out of house arrest in Constantinople and deliver him safely to his sister’s court.

Now, the traditional narrative has it that the Crusaders only wound up attacking Constantinople on the spur of the moment, as their entire expedition was falling apart and the young Alexios offered to throw them a lifeline if they put him and his father back in power. There’s nothing to prove that Boniface and company hashed out any sort of scheme to take the Crusade to Constantinople at the court of Swabia. But it really strains credulity to believe that a would-be king of Jerusalem, a would-be Holy Roman Emperor with general antipathy for the Byzantine Empire and specific antipathy toward its current usurper-emperor, and two children of the deposed Isaac II all spent the holiday season together and the idea of steering the forthcoming expedition to Constantinople never came up at all. And the smoothness with which the Crusaders would eventually turn their focus on to the Byzantines strongly argues against that having been a sudden, unplanned decision. So it’s reasonable to wonder whether the general course of the Crusade was decided at this point. At any rate this is the conclusion Angold and I believe some other modern historians have drawn and I think it makes sense.

Ironically, the Crusade that would eventually sack Constantinople began with a decision not to take the land route through Constantinople en route to its destination. The nobles decided instead to sail in full force directly to Egypt, since an organized invasion was needed to ensure its conquest. Enter our third player, the Venetians. In 1201 the Crusaders contracted with the Doge of Venice, Enrico Dandolo (d. 1205), for a fleet of transport ships and war galleys (for protection) that could carry upwards of 33,000 men, plus another 5000+ animals, to the Holy Land. Venice was the only state in Europe that could possibly have pulled this project off, and even at that it would require devoting the city-state’s full resources toward one aim for an entire year. Understandably, Dandolo wanted a sizable payment for the job—85,000 silver marks—and the Crusaders agreed to pay it.

As you’ve probably already guessed, relations between Venice and the Byzantine Empire at this point were quite poor. Venetian merchants had moved into the Empire during the reign of Alexios I Komnenos (1081-1118) and had established themselves as its dominant commercial player. Emperor Manuel I Komnenos (r. 1143-1180) worked to break their dominance by favoring merchants from other Italian states, primarily Amalfi, Genoa, and Pisa. Commercial rivalries between those communities sometimes turned violent. They really turned violent in 1171, when Venetian merchants in Constantinople attacked the Genoese community in force. Manuel responded by breaking Venice’s commercial power in the Empire, souring Byzantine-Venetian relations. Byzantine residents of Constantinople came to despise virtually all of the Italians in the city, and the accession of Andronikos I Komnenos in 1183 coincided with what was essentially an anti-Italian pogrom in which perhaps tens of thousands of people were massacred by the Byzantine mob. This incident further soured the Empire’s increasingly sour image in Catholic Europe and likely contributed to the sentiments that fueled the Fourth Crusade.

The Zara Expedition

Dandolo and the Venetians lived up to their end of the deal, somewhat amazingly given its scope. The Crusaders…well, not so much. They failed to make their regularly scheduled payments, and when their army finally arrived in Venice, in May 1202, it was more like 11,000 men strong rather than the anticipated 35,000. How did that happen, you ask? Several lords who’d agreed to join the Crusade had decided on their own volition to make separate arrangements for getting to the Holy Land, which they felt free to do because a) they were all more or less peers with Boniface, and b) many of them had no idea that the expedition’s senior braintrust (I use the term loosely) was planning to invade Egypt, because said braintrust hadn’t told them.

As I say, this is where things went off the rails. Boniface had been planning to collect the money to pay the Venetians for their ships by tithing the assembled army—so when about a third of the expected army assembled, he could only raise about a third of the agreed-upon price. Because of the size of this project and the resources he’d had to devote toward it, Dandolo—even if he’d wanted (and he really didn’t)—couldn’t afford to waive or even reduce the Crusaders’ fee, lest he literally bankrupt Venice. This was quite an impasse. But Dandolo had a way for the Crusaders to make good. He wanted them to do a little marauding of Venice’s maritime competitors along the coast of the Adriatic. In particular, he wanted the Crusaders to attack Zara, a city on the Dalmatian coast of Croatia that had once been in Venice’s sphere of influence but had placed itself under Hungarian protection in the 1180s.

This is one of a number of points where the traditional narrative—which has the Crusaders lurching from unforced error to unforced error in the blackest of comedic misadventures that climaxes on the walls of Constantinople—diverges from the arguments of Angold and other contemporary historians. The traditional story is that Dandalo, desperate to extract some value from a project that really had involved a massive investment of resources and had effectively wiped out an entire commercial year for Venice’s merchant community, seized upon Zara. The Crusaders, who in this narrative were equally desperate to find some way to make good on their part of that 1201 contract, agreed in the heat of the moment. Angold and others argue that, like the attack on Constantinople, the attack on Zara was also planned in advance, that it was part of the Crusade’s hidden agenda and was the price of Venetian aid. There is also a middle position here, which is that Dandolo had some inkling that the Crusaders would be unable to pay their tab and had the Zara operation in mind as a plan B, but that the Crusaders themselves acted out of panic a la tradition.

Pope Innocent III, for obvious reasons, was absolutely opposed to a Crusader army attacking a Catholic city, but Dandolo kicked the papal representative out of the army and led it in an attack on Zara. At this point, Innocent threatened to excommunicate the entire Crusade if they proceeded. One of the Crusade’s leaders, Simon of Montfort, told the Zarans that his French forces would sit out the siege in an effort to wash his hands of the affair. But this may have unwittingly compounded the problem by convincing the Zarans that the Crusader army was coming apart at the seams, inspiring them to put up a fight rather than surrender immediately. Neither the pope’s rage nor Simon’s recalcitrance was enough to stop Dandolo, who still had the Crusaders over a barrel and insisted on taking the city—which they did, in late November 1202. Innocent indeed excommunicated the army. However, the following February he rescinded the excommunications of all non-Venetians in the campaign under the supposition that the Crusaders’ hands were tied by the conniving Dandolo. The Crusader rank and file may not have known about any of this because, in something of a theme for this expedition, their leaders didn’t tell them.

On to Constantinople

As it happens, Boniface of Montferrat had been absent for much of these events, having opted to visit his cousin in Swabia again. It may be that he wanted to avoid what promised to be a very unpleasant papal reaction to Zara, or it may be that he wanted to meet again with Alexios Angelos and get his best and final offer for a Crusader attack on Constantinople. Coincidentally or not, Boniface’s return to the Crusader camp coincided with envoys from Swabia bringing just such an offer. Alexios offered to pay the Crusaders’ debt to Venice along with a hefty stipend for the Crusaders themselves and to provide the expedition with thousands of Byzantine soldiers and transportation to Egypt. He even offered to bring the Orthodox Church under papal authority. All the Crusaders had to do was to put him, and his father, back on the throne in Constantinople—an act that Alexios argued was in keeping with the general spirit of the Crusade in that it was restoring the Byzantine Empire’s rightful, God-approved rulers. Whether he’d worked this out with Boniface in advance or had sprung it on the Crusaders without warning, his offer was too good to refuse. It was also impossible for Alexios to fulfill, but we’re not there yet.

Innocent again opposed this move, but not nearly as strenuously as he’d opposed the assault on Catholic Zara. Relations between the Byzantine Empire and Latin Christendom were on the whole not great and I think we can assume the pope was at least intrigued by the idea of the Latins putting Alexios on the throne and thus making him beholden on some level to Rome. Dandolo, meanwhile, was thrilled. Not only would he get paid in full, but as I noted above Venice and the Byzantine Empire were on almost openly hostile terms. It’s entirely possible that Dandolo preferred a Crusader attack on Constantinople to one on Egypt, whose Ayyubid rulers, were at this time pretty good Venetian clients.

There does seem to have been some serious opposition among some of the Crusader nobility and its rank and file, some of whom left the army at Zara. Others would express their opposition during an extended stop on the island of Corfu, but their opposition faltered when Boniface and the other Crusade leaders convinced them that the only way to make a successful campaign in the Holy Land was to restore Alexios and Isaac and thereby secure their promised reward. By this point that was undeniably true, but only because Boniface and company had made it so.

Alexios convinced the Crusaders that they’d be greeted in Constantinople as liberators, to borrow a phrase. But when the army actually arrived outside the city’s walls, it turned out the people of Constantinople were fine with Alexios III being in charge and resisted the Latin interlopers. This complicated the Crusaders’ plans but not that much, as Constantinople was not especially well-defended. That political instability we outlined above led rulers to prefer a relatively small standing garrison in the city and to rely on recalling troops stationed outside the capital in case of any serious threat. But Alexios III hadn’t had time to make those kinds of preparations. The city could rely on its land walls for some protection but it was vulnerable to an attacker who had enough sea power to come at the city from that direction—as the Crusaders and Venetians did.

Alexios III appears to have made an attempt to buy the Crusaders off, but after having convinced their army of the cosmic justice of their Alexios’ cause that wasn’t a deal the expedition’s leaders could make. And so the Crusaders besieged the city and eventually forced Alexios III to flee on the night of July 17, 1203. Isaac II was restored to the throne despite his blindness, and at the Crusaders’ insistence the younger Alexios—now Alexios IV—was crowned co-emperor. Isaac doesn’t seem to have been terribly thrilled with all the things his son had offered the Crusaders to win their support, but he didn’t have much choice but to ratify the deal.

Things went south pretty fast from here, when it became apparent that Alexios IV simply couldn’t fulfill the exorbitant reward he’d promised the Crusaders. He ordered anything of value in Constantinople melted down to pay the foreign army, including religious icons, which enraged the city’s already-pretty-angry residents. Meanwhile the Crusaders, increasingly convinced that Alexios was planning to cheat them, began to raid the surrounding countryside in order to get the reward they believed was theirs. Dissension emerged again within the Crusade, with those who’d been uneasy about attacking Constantinople agitating for a quick departure to the Holy Land—the whole Egypt idea never seems to have been entirely accepted by the Crusader army—while their leaders were intending to stay put until they got what was coming to them.

Caught between his obligations to the Crusaders and his obligations to a Byzantine populace that wanted the Crusaders gone and their deal invalidated, Alexios increasingly oriented himself with the populace and his relationship with the Crusaders broke down. By late 1203 the Byzantines, led by a nobleman named Alexios Doukas (who went by the nickname “Mourtzouphlos”), were in a state of open hostilities with the Crusaders. When an anti-Crusader mob in Constantinople threatened his position, Alexios IV appealed to the Crusaders for assistance but it seems Mourtzouphlos was able to intervene to prevent that assistance from materializing. He then removed Alexios from the throne and took power as Emperor Alexios V Doukas on January 27. Isaac died around this time, though the circumstances seem not to be entirely clear. Alexios IV died not long after, under much clearer circumstances—Alexios V had him strangled.

Given the circumstances under which Alexios V came to power, it’s not terribly surprising that he showed no interest in sticking to the terms of Alexios IV’s deal with the Crusaders. Sources indicate that he and Dandolo did meet to discuss some sort of payoff but that went nowhere and you get the sense that the new emperor badly overestimated the strength of his position. Boniface and the Crusade’s other leaders assembled their army in February 1204 and successfully made the case that the overthrow and murder of Alexios IV was an affront against God that had to be avenged. They even got what was left of the expedition’s clerical arm—those religious officials who’d opposed the attack on Zara and the initial attack on Constantinople had mostly abandoned ship by this point—to approve military action in order to effect Alexios IV’s promise to bring the eastern Church under papal authority.

Endgame

The Crusaders and Venetians probably outnumbered the Byzantine garrison, particularly given that, as Angold notes, some Crusaders who had headed on to the Holy Land over the past year or so wound up meandering back to join the main force because there wasn’t much they could do in the Levant in such small numbers. Westerners resident in Constantinople appear to have at least harbored sympathy for the Crusaders—recall the bad blood that had built up in the city in recent decades—and they appear to have been another resource on the Crusaders’ side. Again going by Angold, it’s unclear when exactly the Crusade leaders decided that they were going to take the city, and the empire—as opposed to, say, putting another puppet emperor on the throne—but they drew up a new arrangement with Dandolo in March 1204 that seems to make their intention clear. The siege began in earnest on April 8 and wasn’t fully over until April 13, but April 12 was the decisive day. A group of Crusaders seized a portion of Constantinople’s sea wall, and the rest was formality.

The Crusaders taking the city, from a 15th century French manuscript (Wikimedia Commons)

On April 13 the cream of Constantinople society offered the imperial throne to Boniface of Montferrat, the leader of the Crusade, but the Crusaders had agreed to put the choice of a new emperor to an election and the Venetians in particular did not want to see Boniface crowned emperor. The winner of the contest turned out to be Baldwin of Flanders (d. 1205), who now became what historians call the Latin Emperor of Constantinople. I’m sure Boniface was real, real happy for him. Salvaging what he could, Boniface made himself the ruler of the new “Kingdom of Thessalonica,” which controlled a large chunk of the European part of the empire as a vassal of Constantinople but was quite short lived—it was conquered by the Byzantine successor kingdom of Epirus in 1224.

Constantinople, meanwhile, was picked clean by the plundering army along with a mob of the city’s Latin residents. Accounts of the sack may exaggerate its violence but likely not its avarice—the Crusader army had been jerked around by pretty much everybody, including its own leaders, for the better part of two years and they appear to have appropriated as much movable wealth as possible (and Constantinople still had quite a bit of that) in compensation. Alexios V had fled the sack but the would-be emperor was captured and executed in December.

The temporary successor states to the Byzantine Empire (LatinEmpire via Wikimedia Commons)

Three successors emerged with claims on the “true” Byzantine throne—the Despotate of Epirus that I mentioned above, under the Komnenodoukas family; the Empire of Trebizond along the southern coast of the Black Sea, under another branch of the Komnenos family; and the Empire of Nicaea, under the Laskaris family. Nicaea claimed the prize when its armies retook Constantinople in 1261, ending the Latin Empire and restoring at least a facsimile of Byzantine rule under new Emperor Michael VIII Palaiologos (the Palaiologos family having by this point usurped the throne from the Laskaris family).

The Palaiologos would rule the empire until it fell to the Ottomans in 1453 while the other two kingdoms outlasted the empire, briefly—the Ottomans took Trebizond in 1461 and the Epirotan capital, Vonitsa, in 1479. But the empire the new dynasty ruled was a shadow of its former self. The Latin interregnum and the costs of retaking Constantinople caused what remained of Byzantine Anatolia to be lost, irrevocably, to Turkish principalities. Constantinople itself, the imperial city, never recovered to what it had been prior to the Crusader sack.

Innocent, when all was said and done, accepted—I’m sure very grudgingly—the copious amount of plundered riches the Crusaders sent Rome’s way. But he seems to have recognized that this fiasco would be the final nail in the coffin for any plans to heal the Great East-West Schism. This proved to be an issue in the 15th century, when Byzantine subjects and Orthodox clergy resisted Latin efforts to raise a new Crusade to help defend what was left of the empire from the Ottomans (many seem to have felt that life under Islam would be preferable to life under Latin Christianity).

Venice was perhaps the crusade’s biggest winner. Hitherto its relationship with the Byzantine Empire had alternated between one of subservience and one of competition, but it would never really be either of those again. Instead Venice transformed overnight from a commercial republic to a maritime empire, dominating commerce in the eastern Mediterranean. It added several strategic former imperial territories (see the map above) and bought more (Crete) from Boniface of Montferrat in 1205 (it finally secured its purchase in 1212). And it ensured that Constantinople would be ruled (at least for a few decades) by a client.

The traditional view is that the Fourth Crusade led directly to the end of the Byzantine Empire in 1453, by dramatically weakening the empire moving forward. This is inarguable, but the point is complicated by several factors. One is that even the weakened empire wound up surviving almost 200 years after its restoration, so it’s not as though 1204 triggered an immediate collapse. It’s also true that the Byzantine Empire was already in political free fall when the Crusaders got there—they probably wouldn’t have been able to take Constantinople otherwise. We further have to contend with the question of whether Constantinople and its walls, the city’s (really the empire’s) greatest defensive asset, could have survived the invention of siege cannon regardless of what happened in 1204.

Those caveats aside, the Fourth Crusade and the Latin interlude were devastating for the Byzantine Empire. They dramatically weakened it in comparison with the Turks in Anatolia, and the restored empire was forced to bleed its countryside dry with taxes to repair the damage that was done, which further weakened its cohesion. I think it is fair to say that the Fourth Crusade, while it didn’t end the Byzantine Empire in the strictest sense, did bring an end to its days as a major world or even regional power. For the rest of its days it would be at the mercy of its more powerful neighbors.