A single book as large as a door. A devil staring from one page; a vision of heaven on the next. For eight centuries the Codex Gigas-nicknamed the "Devil's Bible"-has lured rumor and reverence in equal measure. Giant on Vellum tells its full, human story: from a modest Benedictine house in Bohemia to Rudolf II's Prague of marvels, from the last convulsions of the Thirty Years' War to a midnight rescue from the flames of Stockholm's Tre Kronor.

This biography looks past the nickname to the work itself: a complete Vulgate Bible flanked by Josephus and Isidore, medical recipes, penitentials, calendars, and alphabets-an entire medieval library bound into one disciplined object. We meet the scribe whose steady hand carried the project across years; the binders, clasps, chains, and desks that kept the giant usable; the curators and conservators who read scars as data; and the scientists and photographers whose imaging now lets anyone "turn" its leaves.

Along the way, legend is separated from ledger. What pigments and parchment can prove is weighed against what folktales promise; the "pact" is retired without losing the magnetism of marvels. The result is a portrait of endurance: how knowledge systems, craft, and custodianship allow a fragile thing to outlast empires-and why a medieval giant still matters in an age of glass and pixels.