The Fourth Crusade, which gained sad fame... The crusaders captured and plundered Constantinople - and this was the beginning of the end of the Byzantine Empire. But what made the “soldiers of Christ” do this? Rejection of Eastern Orthodox Christianity, which they considered heresy? A banal thirst for profit? Or maybe the European knights turned out to be ordinary victims of blackmail by the long-time enemy of Byzantium - the Venetian Republic? Jonathan Phillips, relying in his work on many documents that made it possible to explore not only history, but also prehistory of the Fourth Crusade, will give a very unexpected answer to these questions in his book.