The Crusades were not an example of early European colonization of the Middle East, even if they did create some European-ish kingdoms there for a while. That's a much later post- and anti-colonialist view that comes, at least in part, from a Marxist reading of history. In the case of the Crusades, it was argued the knights who went adventuring in the Levant were the second and third sons of wealthy nobles, who, because of European inheritance rules, had little to look forward to by staying in Europe, and lots to gain in terms of plunder by going to the East. Tool theory, bro, but it's not true. First, most of the people who responded to the call to crusade weren't knights at all. They were poor people. And secondly, most of the nobles who did go crusading were lords of estates, not their wastrel kids.