[graemep]

I do not think that stacks up as an explanation. The crusades were not financially remunerative - the crusaders mostly lost money. They might have made money if they were hired as mercenaries though - the famous example of that being the Varangian guard.

I do not think its entirely true to say Christians were "free to plunder and enslave non-Christians". Even against non-Christians war required justification (OK, you can make something up, but there is an extra barrier) and slavery (and slave trading in particular) was increasingly discouraged (until its revival in early modern times, of course).

One of the big examples of a formerly Viking people participating in the crusades was Norman Sicily which was one of the most enlightened (religious freedom, for example) societies of its time.

The Normans also settled down in Normandy and England and stopped raiding.

[lukan]

"I do not think its entirely true to say Christians were "free to plunder and enslave non-Christians""

Well, I am not a historian, but was there any war against pagans, that was stopped by the church or individual priests?

(talking about medieval times, modern christianity is a bit different, but the old tradition seems to get a revival in certain circles)

The most I know of, is individual priests who for example criticize the acts of the conquistadores. But crusades to "spread" christianity were rather pushed as a sure way to get into heaven as far as I know.

"The crusades were not financially remunerative - the crusaders mostly lost money."

That is probably why they stopped doing it. Before christianity they had all the coasts of europe to blunder. After their kings turned christians who made treaties with the mainland christian empires - that was not possible anymore and raiding, even under the disguise of crusade, much harder and therefore less attractive (apart from that I did not claim that my explanation is the explanation, just a contributing factor)

[graemep]

> Well, I am not a historian, but was there any war against pagans, that was stopped by the church or individual priests?

I recall reading a priest or monk influenced Charlemagne to stop/moderate his persecution of pagans. I very much doubt this was the only example, just one I have read about.

> But crusades to "spread" christianity were rather pushed as a sure way to get into heaven as far as I know.

In very specific cases, most notably the liberation of Jerusalem, not in general.

> That is probably why they stopped doing it.

Crusades went on for about 400 years if you count things such as the Reconquista

I also find it hard to believe they could not find profitable wars. It was not difficult to find an excuse for war. Being Christians did not prevent either Harald Haraddra or William the Conqueror from invading England.

> The most I know of, is individual priests who for example criticize the acts of the conquistadores

It was more than just scattered individuals voicing criticism. It was a movement that lead to action and legislation: https://en.wikipedia.org/wiki/Protector_of_the_Indians

[lukan]

"Crusades went on for about 400 years if you count things such as the Reconquista

I also find it hard to believe they could not find profitable wars."

Well, sailing from norway to england, do some raiding then come back before the winter sounds way easier, than sailing from norway to the middle east and back. So it has been done, but apparently was not so worth it.

https://en.wikipedia.org/wiki/Protector_of_the_Indians

And here thanks for the link, I know little of that time, but I am not so sure if it counts as protecting pagans, or protecting baptized pagans who are christians.

[graemep]

Both I think.

If you are interested in the conquistadores the Rest is History podcast series on the conquest of the Aztec and Inca empires is excellent, especially the latter.