Margen
The National Library of Sweden holds the Codex Gigas, a thirteenth-century manuscript nearly a metre tall and weighing around 75 kilos, made from the skins of some 160 animals. It is the largest medieval manuscript to survive.
Its nickname comes from an illustration: an entire page devoted to a portrait of the devil. Legend has it that a monk condemned to be walled up alive promised to write, in a single night, a book containing all the world's knowledge — and, seeing he wouldn't make it, asked for help from exactly the wrong party.
The reality is almost more incredible: analysis of the handwriting suggests it was copied by a single person, in a labour that may have consumed decades of his life.
It reached Stockholm as war booty in 1648, when Swedish troops carried it off from Prague. The devil, it seems, travels too.