The Fourth Crusade and The Sack of Constantinople

A detailed narrative of the Fourth Crusade (1202–1204), which infamously veered from its original goal of liberating Jerusalem to the catastrophic sack of Constantinople, the heart of the Byzantine Empire. Phillips, a Professor of Crusading History at Royal Holloway, University of London, leverages his expertise to present a vivid account, marking the 800th anniversary of the event with a focus accessible to both scholars and general readers.

The crusade began in 1202 when Pope Innocent III called for a mission to reclaim Jerusalem, lost after the Third Crusade. Crusaders, primarily from France and the Holy Roman Empire, gathered in Venice, agreeing to a contract with Doge Enrico Dandolo to transport 30,000 men. However, insufficient numbers arrived, leaving a debt of 34,000 silver marks. Dandolo redirected the crusade to sack Zara, a Christian city under Hungarian control, to offset costs, despite Innocent III’s excommunication threats. The turning point came with Alexius Angelus, son of the deposed Byzantine Emperor Isaac II, who promised funds and reunion of the Orthodox and Catholic churches if restored. The crusaders attacked Constantinople in July 1203, reinstating Isaac and Alexius IV, but their inability to pay led to Alexius IV’s murder by Alexius V (Murtzuphlus) in 1204.

Stranded and hostile, the crusaders besieged Constantinople again in April 1204, breaching its famed walls with Venetian ships and scaling towers. The sack that followed was brutal: churches like Hagia Sophia were plundered, relics stolen, and thousands massacred or raped, with estimates of deaths ranging from 2,000 to 10,000. The city was divided among the victors, establishing the Latin Empire under Baldwin of Flanders, though it lasted only until 1261 when the Byzantines reclaimed it. Phillips uses diverse sources—chronicles by Robert of Clari and Niketas Choniates, papal letters, and troubadour songs—to trace the motivations of leaders like Dandolo, Boniface of Montferrat, and Baldwin, framing their actions as a mix of religious zeal, economic necessity, and political opportunism.