@peterbrown I think that's more bookland/charter land (=permanent tenure for entities smaller than a sovereign, aka it's not a gift economy where the king rewards service but it all resets when anyone involved dies) rather than feudalism as such; feudalism works pretty well, and arguably better, pre-bookland.
And, yes, growth of wealth because this is the invention of private property. It's enclosure zero, the idea that land is a thing you can own. (As distinct from hold.)