Pseudo-Dionysius the Areopagite

An anonymous Syrian monk who wrote under the name of a first-century Athenian converted by Paul, and thereby handed Proclus's metaphysics to Christendom with apostolic credentials attached. Whole passages track Proclus closely. The forgery held for a thousand years; Lorenzo Valla and Erasmus put the first real cracks in it.

The other great productive misattribution in this pack. Two books carried this tradition across two religions, and both of them lied about who wrote them — and both lies worked because the borrowed name got the content read.