What if Constantinople had held against the Fourth Crusade?
In April 1204 crusaders and Venetians stormed and sacked Constantinople. What if the sea walls had held?
What actually happened
The Fourth Crusade was meant to attack Egypt. Its leaders contracted with Venice in 1201 for a fleet to carry over 30,000 men, but far fewer arrived and they could not pay. To work off the debt they helped Venice take the Christian city of Zara in 1202, and then accepted an offer from the exiled Byzantine prince Alexios Angelos: restore his father Isaac II to the throne in Constantinople, and he would pay them handsomely and support the crusade.
In July 1203 the crusaders attacked the city; the emperor Alexios III fled and Isaac and his son Alexios IV were installed. The money never materialised. Alexios IV was murdered in early 1204 by Alexios V Doukas, who defied the crusaders. Their first assault on 9 April 1204 failed. On 12 April, with the wind driving their ships against the towers of the Golden Horn sea walls, they got men across on flying bridges and broke in.
The sack lasted three days and was one of the great cultural catastrophes of the Middle Ages. The crusaders set up a Latin Empire under Baldwin of Flanders, while Byzantine successor states formed at Nicaea, Epirus and Trebizond. Nicaea retook Constantinople in 1261, but the restored empire never recovered its strength.
The turning point
The city was taken at the second attempt after the first had failed, and the eyewitness Robert de Clari makes clear how much depended on the wind bringing two ships up against a tower. Had the defenders, including the Varangian Guard, held a second time, the crusade's leaders would have faced unpaid troops, a Venetian fleet with its own priorities and no way forward.
Historians long debated whether the diversion to Constantinople was a plot by Venice or by the German king Philip of Swabia. Donald Queller and Thomas Madden argued influentially that it was a chain of accidents and bad bargains; Jonathan Phillips and others emphasise the crusaders' desperation and Byzantine political chaos. Either way, the final assault was a close-run thing.
The world that might have been
In Crown & Plough the alternative reads: the Varangian Guard on the sea walls pushed the ladders away; having wintered with neither money nor ships left, the crusaders scattered, and the Emperor's city stood as it had for a thousand years. The game then removes the scripted Latin Empire.
Beyond the game, a Byzantium spared the sack would have kept its capital, its treasures, its administration and its control of the Straits. It would not have been safe: the empire had been weakened by civil war, the loss of Asia Minor to the Seljuks and Norman attacks, and its quarrel with the Latin West would not have disappeared. But a stronger Byzantium might have resisted the rising Ottomans far better in the fourteenth century.
The schism between the Greek and Latin churches, sharpened into lasting bitterness by the sack, might also have stayed a dispute among clergy rather than a popular grievance. Venice, on the other hand, would have lost the Aegean colonies that made it a maritime empire.
Ripples through time
This turning point has no direct links to later medieval ones in the game, but it carries into the Renaissance era. If Constantinople held, the 1500 map still has a Byzantine Empire holding Constantinople and Thrace, ruled by the Laskaris dynasty and hostile to the Ottomans, whose sultan has not crossed its walls. That changes the setting for the Ottoman advance on Vienna.
- Carries into the next era Renaissance and the Age of Discovery
Play this turning point
Start in the Middle Ages (1200), or take the scenario The Galleys of Venice, which begins in 1202 with indebted crusaders stranded on the Lido. The Currents of History story Fourth Crusade lets you join the crusade or defend Constantinople.
The odds weigh Byzantine strength against the crusaders backed by Venice, and the crusaders start strongly favoured. Defending the city, or ruling land on the Byzantine side, is how you change history.
Play this turning point → Start the scenario “The Galleys of Venice” →
Questions and answers
Why did the Fourth Crusade attack Constantinople?
The crusaders owed Venice money for their fleet and accepted the exiled prince Alexios Angelos's promise of payment and support if they restored his father. When those promises collapsed, they attacked the city themselves in April 1204.
When was Constantinople sacked?
The crusaders broke in on 12 April 1204 and sacked the city for three days.
Did Byzantium recover?
The Empire of Nicaea retook Constantinople in 1261, but the restored empire was much weaker and fell to the Ottomans in 1453.
Sources and further reading
Geoffrey of Villehardouin, The Conquest of Constantinople; Robert de Clari; Niketas Choniates, Annals. Modern accounts: Donald Queller and Thomas Madden, The Fourth Crusade; Jonathan Phillips, The Fourth Crusade and the Sack of Constantinople.
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