Here's an odd one. In 1714 the scholar Chrisostome Matanasius published Le chef-d'oeuvre d'un inconnu (The Masterwork of an Unknown), an extensive analysis of a poem he had just discovered. So far nothing unusual except that the book is well over 300 pages of dense text and the poem itself a mere 40 lines.
You've probably guessed that the book was a hoax, a precursor to Nabokov's Pale Fire. It's stuffed with material - the prefaces alone are in French, Greek, Latin, English and Dutch, not to mention an introductory letter and an ode to the author. (One edition may have had fake Hebrew but not the one in the link.) It's a full-blown satire of scholarship. For instance, the "remarks" to the first stanza spend five pages just on the name Colin with an apparently irrelevant digression on Homer's choice of a nymph's name. As far as I can tell the book has never been translated into English.
The actual author was Thémiseul de Saint-Hyacinthe (1684–1746), a writer, freethinker and bit of a libertine. He had a long dispute with Voltaire (the letters have been published), became a member of the Royal Society, translated Cervantes and Defoe, served as a cavalry officer (and was taken prisoner), and wrote a bestselling novel (The Story of Prince Titi which was translated into English).
https://archive.org/details/lechefdoeuvredu00hyagoog/page/n6/mode/2up?ref=ol&view=theater
