[The Iguana]

The Turks certainly had something to do with it.

And it was because they had overrun Asia Minor that the Byzantines asked Pope Urban for aid in the first place.

Somehow Ridley Scott skips over that part.

[GoLightly]

I wasn't asking if Ridley Scot went into it. I'm asking about Sir Steven Runciman. The Turks got their hands on Constantinople in 1453, well after the era of the Crusaders.