[hearsathought]

The roman empire ( eastern portion anyways ) lasted until the ottoman turks took them out in the 1400s. So the crusades definitely happened during the roman empire's existence.

[egberts1]

I think Roman Empire was split clearly East/West.

Crusade came from the West. Roman Empire, or what the last vestiges of, fizzled in the East.

[SauciestGNU]

Not acknowledging the Roman Empire when it was seated in Constantinople is kind of peak Western chauvinism though.