While it's true that Tolkien did set out to create a fictional world, I think that treating LotR like a historical documentfrom that fictional world is counter to both Tolkien's intent, and the spirit of the work. Tolkien did not write LotR to describe "facts" from some world; rather, he set out to create a mythology for that world. Thus, when you read any ot Tolkien's works, don't think of them as literal descriptions of things that actually occured in some fictional world where elves and wizards exist. Rather, understand it like you would a folk tale or mythic poem: of great cultural significance to the people that it came from, but not a literal account of something that happened.