An assessment of the schools of thought on the Fourth crusade.

The Fourth Crusade has long puzzled scholars, particularly concerning its diversion to Constantinople. This essay examines the competing explanations for the diversion: conspiracy theory, accident theory, and the impact of long-term relations between Byzantium and the Latin West. Conspiracy theorists argue that the Doge of Venice, Boniface of Montferrat, and Phillip of Swabia orchestrated the diversion for political and financial gain. However, the essay refutes these claims, citing a lack of definitive evidence. Instead, it contends that accident theory — suggesting the diversion resulted from unintended events driven by financial miscalculations and Prince Alexios' unfulfilled promises — provides the most convincing explanation. The essay also explores Byzantium’s fragile internal state and deteriorating relations with Venice and the Latin world, though it finds these factors secondary. While acknowledging the merits of conspiracy theories, the essay concludes that accident theory offers the most substantiated and logical account of the Fourth Crusade.