A Bohemian legend has it that when a medieval monk from the Czech town of Podlažice was sentenced to live entombment, a punishment in which someone was permanently sealed inside a confined space and left to die. He tried to earn back his freedom by writing the biggest book ever written—in the span of a single night. Unable to finish this impossible task by himself, he called on the Devil for help—a deal that allowed him to keep his mortal life at the cost of his immortal soul.

This is but one of many ghost stories attached to the Codex Gigas, an illuminated manuscript from the early 13thcentury. True to its name (Latin for “big book”), the Codex Gigas dwarfs all other medieval documents that have survived into the present. Measuring roughly 36 by 20 inches and weighing 165 pounds, its 310 leaves of parchment—made not from paper but vellum or leather—must have required the skins of more than 160 calves and donkeys

What’s inside the Codex Gigas?

Unlike most other illuminated manuscriptsfrom the Middle Ages, the Codex Gigasconsists of multiple, separate texts. Aside from the Old and New Testament, it contains handwritten copies of historical and scientific writings by the Jewish historian Flavius Josephus and the Catholic theologian Isidore of Seville, as well as an early history of Bohemia (the region in which Podlažice is located) by Cosmas of Prague. Also included are lists of incantations and spells, a 12th century medical textbook, a calendar, and overviews of the Greek, Hebrew, and Slavic alphabets.

However, the most famous feature of the Codex Gigas—which earned it the nickname “Devil’s Bible”—is a full-page illustration of a demonic figure with horns, claws, a forked tongue, and large, white eyes. This disturbing image—wedged between a text on penitence and another on exorcising evil spirits— – faces a page containing an equally large illustration of the Heavenly City, possibly symbolizing the two sides of the Christian afterlife.

a yellowed page from an old book showing a large illustration of a demonic figure with horns and fangs and a large forked tongue underneath wide white eyes


A close-up of the illustration that gave the “Devil’s Bible” its nickname. 

Photo: MICHAL CIZEK/AFP via Getty Images.

The history of the Codex Gigas is as mysterious as the meaning behind its illustrations. Unsurprisingly, scholars don’t think that the manuscript was written in one night. Instead, it’s thought to have been composed between 1204 and 1230 AD, likely by a single person. While we can’t know for sure that the Codex was made in Podlažice, a note on the first page identifies the town’s monastery as its earliest known owner. The same note says that the Codex was given to another monastery in 1295, only to be purchased by yet another religious order that same year.

Where is the Codex Gigas now?

From here, an incomplete record of ownership provides a rough sketch of the manuscript’s journey through the ages. In 1594, it fell into the hands of Rudolf II, Holy Roman Emperor and well-known admirer of all things occult. Brought to Prague, it was taken to Stockholm after the Swedish Army won a strategic victory in the Thirty Years’ War.

Kept at Sweden’s National Library, where it remains to this day, the Codex Gigas has continued to find itself at the center local legends. A Swedish text published in 1858, for example, tells the story of a guard who once fell asleep inside the library’s main hall and awoke to find the Codex floating through the air, leading other floating books in a paranormal dance. The guard, it was said, “was and remained feeble-minded from that day on and had to be admitted to the madhouse.”

Also worth mentioning is a rumor concerning the acclaimed Swedish playwright and novelist August Strindberg. According to a friend and fellow writer, Strindberg - who once worked at the library and, like Rudolf II, had a lifelong interest in the occult - would sneak into the building at night, strike a match, and read from the Devil’s Bible in the hopes that doing so would bring him into contact with the underworld.