https://en.wikipedia.org/wiki/Crusades> The first Crusaders had a variety of motivations, including religious salvation, satisfying feudal obligations, opportunities for renown, and economic or political advantage.
"prestige" could be close to "renown", but it comes from a different place (renown brings direct advantages, including nobility attribution for instance), and you'll note economic and political advantage are set as anchors of this list.
The reality of it is about conquering territory under a pretense that won't raise hostility among your neighbors (who can even participate in the expeditions under the same religious flag)
> Trojan war
https://en.wikipedia.org/wiki/Trojan_War
> Many scholars believe that there is a historical core to the tale, though this may simply mean that the Homeric stories are a fusion of various tales of sieges and expeditions by Mycenaean Greeks during the Bronze Age.
> WWII
> proved more important than the economic motives
Could I ask for more details on your understanding of it as "proved" ?