The Glossa Ordinaria on the Bible was the ubiquitous text of the Middle Ages. Compiled in twelfth-century France, this multi-volume work, containing the entire text of Scripture surrounded by a commentary drawn from patristic and medieval authors, is still extant in thousands of manuscripts, testifying to the centrality of the work for generations of medieval scholars. Although the Glossa has been the subject of modern study, it is surrounded by myth. This book, based on manuscript evidence, is the first to draw together the history of this monumental work, its authorship, content, layout, production and use. Raising new questions, and pointing the way to further research, it opens up the Glossa to all students of medieval religion and intellectual history.