No one knows who wrote The Travels of Sir John Mandeville. There is no record of an English knight alive at the right time with that name who could have written it. One oft-repeated theory is that Mandeville retired to Belgium, lived under a pseudonym, and only confessed his authorship of the Travels on his deathbed. Other than the uncorroborated word of a Liege notrary, though, we have nothing to substantiate this theory.
What we do know is that the work was not wholly original, and combined elements of several pre-existing fantasies and romances into a single narrative. And, despite or maybe because of the fantasy elements, it did so well. It remains a fascinating look at what it means to encounter the unfamiliar, to travel, and to see the world that lies just beyond the lands you know.
Theme music: Cowboy Surfer by the Vivisectors