Made from more than 160 animal skins and needing two people to lift it, Codex Gigas, also known as the Devil’s Bible, was allegedly written in just one night.

Herman the Recluse was a 12th century Bohemian monk. Legend has it that he was walled up inside of his cell, condemned to atone for his sins by inscribing holy texts for the rest of his days. To complete the great task more quickly and release himself from an early grave, the monk made a pact with the Devil.

With the Devil’s aid, the monk supposedly wrote the book in a single night. The first half of the tome comprises the entire Latin Vulgate Bible. The remainder is a bizarre mixture of Ancient medical treatises, encyclopedias, chronicles and magical formulae. The colossal Codex even contains a portrait of Lucifer, purportedly drawn by the fallen angel himself.

In experiments conducted to recreate the work, it has been estimated that reproducing the calligraphy alone, without the illustrations or embellishments, would have taken 5 years of non-stop writing. Most scholars believe that, working at a regular pace, it should have taken the monk around 30 years. However, academics have remarked at the stability of the handwriting found throughout the book. The suggestion being that the Devil’s Bible must have been written over a very short period of time.