The Codex Gigas (English: Giant Book) is the largest extant medieval manuscript in the world. It is also known as the Devil's Bible because of a large illustration of the devil on the inside and the legend surrounding its creation. It is thought to have been created in the early 12th century in the Benedictine monastery of Podlažice in Bohemia (modern Czech Republic). It contains the Vulgate Bible as well as many historical documents all written in Latin. Eventually finding its way to the imperial library of Rudolf II in Prague, the entire collection was taken as war booty by the Swedish in 1648 during the Thirty Years' War, and the manuscript is now preserved at the National Library of Sweden in , on display for the general public.
The codex is bound in a wooden folder covered with leather and ornate metal. At 92 cm (36 in) tall, 50 cm (20 in) wide and 22 cm (8.7 in) thick, it is the largest known medieval manuscript. Weighing 74.8 kg (165 lb), Codex Gigas is composed of 310 leaves of vellum allegedly made from the skins of 160 donkeys or perhaps calfskin. It initially contained 320 sheets, though some of these were subsequently removed. It is unknown who removed the pages or for what purpose but it seems likely that they contained the monastic rules of the Benedictines.
Legend has it, that it was written by one scribe in one night.
According to legend, the Codex was created by Herman the Recluse in the Benedictine monastery of Podlažice near Chrudim in the Czech Republic. The monastery was destroyed sometime in the 15th century during the Hussite Revolution. Records in the codex end in the year 1229. The codex was later pledged to the Cistercians Sedlec Monastery and then bought by the Benedictine monastery in Břevnov. From 1477 to 1593, it was kept in the library of a monastery in Broumov until it was taken to Prague in 1594 to form a part of the collections of the Emperor Rudolf II.