[paudio]

The crusades did more to destroy the Byzantine Empire than the Turks.

They might have. But it's irrelevant to the argument that the Muslims did capture Constantinople, the second Rome. Plus, it's not like the Muslims was never trying to attack the city before it finally fell.

[DariusBane]

That is a monumental understatement to say that the crusades "might have" contributed. to the end of the Byzantine empire.

The fourth Crusade was essentially used by the Venetians as a ploy to assemble an army and send it against Constantinople. The Christian east never recovered, and left a power vacuum that the Arab Muslims exploited. If you want to argue who started it, and what sparked the first Crusade, and the second and the Richard The Lion Hearted and his third crusade, that was the result of the Arab Muslim Tsunami destroying the Greek world that had existed since Alexander the Great. This included the Ptomlomics, the Seleucid's etc. But to argue that the fourth Crusade was not an evil power grab by scheming Venetians that destroyed the Christan East is just silly.