How and when the Byzantine Empire could have turn feudal?
NB : Feudalism as defined there
-Vassalic relations and commendation present at every scale of society (or at least among the elites)
-Principe of inheritence of title (not compulsatory, but at least as the traditional transmission)
-Mix of fiscal and territorial powers within a "fee" or a "benefit"
-Property of land is a bonus, but not compulsatory outside the proper land of the noble
So no "Feudalism is just a state ruled by warriors", thanks.