National Geographic Society Newsroom

Devil’s Bible Darkest Secrets Explained

It’s a mysterious book that in its day was believed to contain all human knowledge. But why did medieval people believe that the author sold his soul to the devil to be able to write it? The “Devil’s Bible,” a behemoth volume weighing in at 165 pounds, believed to have been produced by a single monk...

It’s a mysterious book that in its day was believed to contain all human knowledge. But why did medieval people believe that the author sold his soul to the devil to be able to write it?

The “Devil’s Bible,” a behemoth volume weighing in at 165 pounds, believed to have been produced by a single monk over the course of decades in the 13th Century, is the focus of a documentary that was featured on the National Geographic Channel.

A complete Old Testament and New Testament, and a collection of a number of secular works besides, the Devil’s Bible is an encyclopedia of medieval knowledge. But it has also been haunted by dark speculation, including that its writing was guided by the devil’s hand.


Devil’s Bible Photo open on the page of the picture showing Satan © MHP

It got its name “Devil’s Bible” from the illustration of the devil on page 290 (in the photo above). It is believed to be the only bible of its era that depicts Satan. There the devil is, looking more like a cartoon character in an ermine diaper, rather than evil incarnate.



Devil’s Bible (Codex Gigas) manuscript © MHP

What makes the Devil’s Bible such an object of fascination is the back story associated with it. According to the TV show, which I watched when it premiered, the legend about the Devil’s Bible was that it was written by a monk in a single night.

Compact with the devil

The story goes that such a feat was possible only because the monk had made a compact with the devil. The implication is that the devil himself wrote this bible, which is why his portrait adorns it.

Devils-Bible_3.jpgHowever, if the devil inspired the book then there is nothing in it that appears to cast Satan in a good light, at least not that I can find by searching for information on the Web about the Devil’s Bible. (It is more properly known as Codex Gigas, or “Giant Book.”)

Codex Gigas manuscript © MHP

Oldest Bible Reunited Online >>

The television show combined the story and the extraordinary history of this giant book with modern forensic science to see what can be established about the Devil’s Bible. The manuscript was definitely produced by one person, according to analysis of the ink and penmanship.

Most likely the producer of the Devil’s Bible was a monk whose name is mentioned in the index and who probably devoted many, many years to the task, perhaps as a form of penance. The Devil’s Bible was written by one person, but it was not written in a single night.


Devil’s Bible (Codex Gigas) manuscript © MHP

Courtesy of National Library of Sweden.
Photograph courtesy of the National Library of Sweden. The Devil is shown alone, in an empty landscape, the Library of Sweden says on its website. “He is crouching with his arms held up (he has only four fingers and toes) and wears an ermine loin cloth. Ermine is usually associated with royalty, and its use here is to emphasize the position of the Devil as the prince of darkness.” The portrait was intended to remind the viewer of sin and evil, the Library website continues. “It is opposite a page with a representation of the Heavenly City and the two pages were deliberately planned to show the advantages of a a good life and the disadvantages of a bad one.”
Photograph courtesy of the National Library of Sweden
Photograph courtesy of the National Library of Sweden

Portraits of the Devil are common in medieval art, but this one in the Codex Gigas may be unique in books for showing him alone and occupying a whole page. The Heavenly City (photo on the left) and the Devil Portrait are the only full page pictures in the Codex Gigas.

The provenance of this extraordinary book and its unlikely story as well as its journey across centuries, passing through a succession of monasteries and royal palaces to its current destination, the National Library of Sweden, is a legitimate story for National Geographic to cover. And it makes good television too.


Exorcism and Magic Spells in the Devil’s Bible

Also included in the Devil’s Bible, on pages that follow the picture of the devil, (the picture below), are detailed instructions for the exorcism of demons or evil from people and objects.


There are also two magic spells, both with specific instructions on how to identify and catch a thief.

Possession by demons was commonly thought during medieval times to be the cause of many illnesses.

The church had specific rituals to exorcise evil by casting demons out of an afflicted person’s body.

In the name of Jesus

According to the Christian New Testament, Jesus gave his disciples the power to cast out evil spirits, which is why scholars believe the medieval exorcists commanded demons to leave an afflicted person’s body “in the name of Jesus Christ.”

The incantations for exorcism would not be out of place in the Devil’s Bible, appearing after this picture of the devil.

Devil’s Bible facts:

  • The 310 parchment leaves (620 pages) of the Devil’s Bible are made of vellum, from the processed skins of 160 animals, most probably donkeys. Some pages of the Devil’s Bible are thought to have been removed, and no one knows what happened to them.
  • The entire Devil’s Bible is written in Latin. The calligraphy is lavishly luminated throughout.
  • Including its wooden case, which is ornamented with metal, the Devil’s Bible is so heavy (about 165 pounds) that it requires at least two adults to carry it.
  • The portrait of the devil faces a picture of the “City of Heaven,” the only other image in the Devil’s Bible. Some scholars believe that the picture of Heaven negates the portrait of the devil. Others have noted that no people can be seen in the City of Heaven.
  • Also in the Devil’s Bible is the “encyclopedia” by St. Isidore, who, more than a millennium after he lived, is regarded as the patron saint of the Internet. Isidore’s Etymologiae was an attempt to record all universal knowledge of his time, the 7th Century.


Devil’s Bible additional information:

Codex Gigas (Official Codex Gigas site at the National Library of Sweden, contains highlights and scholarly analysis of the Devil’s Bible.)

Codex Gigas (World Digital Library’s full digital scan of the entire Devil’s Bible)

Manuscriptorium (Czech-language site’s high-res scans of the Devil’s Bible)



David Maxwell Braun is director of outreach with the digital and social media team illuminating the National Geographic Society’s explorer, science, and education programs.

He edits National Geographic Voices, hosting a global discussion on issues resonating with the Society’s mission and major initiatives. Contributors include grantees and Society partners, as well as universities, foundations, interest groups, and individuals dedicated to a sustainable world. More than 50,000 readers have participated in 10,000 conversations.

Braun also directs the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship.

Follow David on Facebook  Twitter  LinkedIn

About National Geographic Society

The National Geographic Society is a global nonprofit organization that uses the power of science, exploration, education and storytelling to illuminate and protect the wonder of our world. Since 1888, National Geographic has pushed the boundaries of exploration, investing in bold people and transformative ideas, providing more than 14,000 grants for work across all seven continents, reaching 3 million students each year through education offerings, and engaging audiences around the globe through signature experiences, stories and content. To learn more, visit or follow us on Instagram, Twitter and Facebook.

Meet the Author

David Max Braun
More than forty years in U.S., UK, and South African media gives David Max Braun global perspective and experience across multiple storytelling platforms. His coverage of science, nature, politics, and technology has been published/broadcast by the BBC, CNN, NPR, AP, UPI, National Geographic, TechWeb, De Telegraaf, Travel World, and Argus South African Newspapers. He has published two books and won several journalism awards. In his 22-year career at National Geographic he was VP and editor in chief of National Geographic Digital Media, and the founding editor of the National Geographic Society blog, hosting a global discussion on issues resonating with the Society's mission and initiatives. He also directed the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship, awarded to Americans seeking the opportunity to spend nine months abroad, engaging local communities and sharing stories from the field with a global audience. A regular expert on National Geographic Expeditions, David also lectures on storytelling for impact. He has 120,000 followers on social media: Facebook  Twitter  LinkedIn