The 800-year-old book that supposedly contains the devil's portrait

The Codex Gigas. No, this isn't the name of a companion piece to the Necronomicon, or the sacred tome for a race of cosmic necromancers from Warhammer 40k. It's an actual, 165-pound, 620-page tome composed of donkey-skin vellum and an ornamented, wood-and-metal cover. Discovered in Prague in 1648 by the Swedish army during the Thirty Years' War, the Devil's Bible (as it's commonly called) is the largest known book written during the medieval ages, at 36 inches tall, 20 inches wide, and 8.7 inches thick, per Book Riot. The Codex Gigas literally means "giant book," and its origins are a subject of speculation, mystery, and legend that involves, among other things, an actual pact with the Devil.

The Codex Gigas gets its nickname "Devil's Bible" from a standout feature on page 290: a depiction of the Devil, Satan, Lucifer, Prince of Darkness — whatever name you give him – crouching with his arms upstretched and his body wrapped in loincloth. This image is unique amongst all medieval literature because it's not surrounded by anything on the page – just the Devil himself, at 19-inches tall. The admittedly menacing image, and the arcane, uncanny composition of the book itself, has somewhat colored scholarly research into the tome. At present, though, best estimates place the Codex Gigas at a 13th-century origin somewhere in the modern day Czech Republic, as stated by National Geographic.

A book to end all books

The author of the Codex Gigas is unknown, however it's believed to be the work of a single monk, not multiple authors, because of stylistic consistencies in handwriting and construction. This is unusual in and of itself, and taking into account the mammoth size of the book, the amount of text, the attention to detail in its construction, the effort put into the book's illuminations (actual gold or silver paint filigreed onto pages), scholars believe it was written as an act of penance. In fact, it would have taken over 30 years to complete. Hence one of the legends surrounding it: the monk made a pact with the Devil to finish it in one night.

But what does the Codex Gigas actually contain? As it turns out, the book seems to be a compendium of historical information; a book to end all books. The Codex Gigas houses, among other things: a full Christian Bible, "the texts The Jewish War and Jewish Antiquities by Flavius Josephus (37–100 CE), an encyclopedia by St. Isidor of Seville (560–636 CE), and The Chronicle of Bohemia written by a Bohemian monk named Cosmas (1045–1125 CE)." It also contains a number of smaller texts about medieval practices, exorcism, as well as magic spells about how to identify and catch thieves. Some pages have been ripped out, and across from the picture of the Devil is the "City of Heaven," without a single soul walking around inside of it.