Storage:

Rather than storing books upright on shelves as we do in the modern era, medieval bookkepers kept them lying horizontal in chests or cupboards.  In fact, our modern library, a room designed specifically for the storage of books, did not come into existence until the late medieval period.  Most of our knowledge on this topic comes from textual references and manuscript illustrations, which depict books as laying flat on shelves and rarely, if ever, in bulk.  Whether in chests or in cupboards, however, books were usually "grouped by broad subject categories to aid finding" (Graham and Clemens 58). In fact, Humbert of Romans, the former master general of the Dominican order, demanded that the Dominicans arrange their book collections by subject, writing:

"Moreover, the cupboard in which the books are stored should be made of wood, so that they may be better preserved from decay or excessive dampness; and it should have many shelves and sections in which books and works are kept according to the branches of study; that is to say, different books and postils and treatieses and the like which belong to the same subject should be kept separately and not intermingled, by means of signs made in writing which ought to be affixed to each section, so that one will know where to find what one seeks" (Graham and Clemens 58).

Even after the rise of the modern library, in which books were collected and stored in bulk, medieval librarians would turn the books "with their spines facing inward and the fore-edges outward," explaining why with many medieval manuscripts the book titles were written across the page edges (Graham and Clemens 58).  Some manuscripts also include a library shelfmark "usually entered on a front endleaf or one of the first pages of text and occasionally repeated at the back of the book" (Graham and Clemens 59).  These shelfmarks allow modern-day scholars to reconstruct the manner in which these manuscripts were grouped in the proto-libraries of the Middle Ages.

Books in the thirteenth century were sometimes chained to their shelves as a means of preventing theft.  The earliest chained libraries stored books on "a long, sloping lectern at which several readers could sit if there was a bench and stand if there was not" (Graham and Clemens 60). Later chained libraries did allow the books to be stored on shelves; however, the chain had to be long enough to allow the book to be removed and placed on a nearby desk for reading.  Book theft was certainly a problem in medieval times, as evidenced by the number of chained libraries and prevalence of antitheft technology.

Below is the image of the back binding of a manuscript. Near the top center of the cover is a mark from a chain that once bound it to a library shelf.