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The Crusades - Pilgrimage or Holy War?: Crash Course World History #15
Okay, the 4th Crusade, the crazy one. The Crusaders were invited by the Venetians to use boats to travel to Jerusalem. Instead of payment, were asked by the Venetians to conquer back the city of Zara across the Adriatic, I think in modern day Crotia. The Crusaders did so, and then both they and the Venetians were ex-communicated by the Pope.
Then, invited by the "would be" emperor Alexius 3rd of Byzantium [his father was a disposed emperor], and promised money if they would help him. He had issues and was slow in paying, Mourtzouphlos took over, also slow in paying.
Crusaders sack Constantinople in 1204.
Yea, altogether a real mess. Never invited armed soldiers to a city and then be slow in paying them.
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PS I'll admit that I'm jealous of John Green, and tends to think he gets a lot of overhype, I mean, both his books and his movies for crying out loud. But on this one I think he does pretty well.