I have a player whose character's backstory ties into the Mendevian Crusades, and I'd love to build some hooks around that in our campaign. But I haven't found much lore about the crusades, beyond the sidebars in the _Lost Omens World Guide_. Any pointers?
I believe the Fifth Crusade is basically the Wrath of the Righteous AP for P1e.
Apart from the old Campaign Setting and Inner Sea World Guide, Pathfinder Wiki lists The Worldwound as a reference for the Fourth Crusade, but it's just a paragraph with basically the same material as in the Wiki.
Oh, thanks! The page you linked to has some great background.