This is the first handbook on medieval glossography. Written by acknowledged experts in the field, the work introduces the reader to the subject and history of glossography, and in a comprehensive documentation section it provides an overview of glossed texts, of the chronological and geographical distribution of glossed manuscripts and of the quantity of texts involved. There is a detailed treatment of the codicological and palaeographical aspects of the glosses, interlinear glosses and glossaries are presented either using exemplars or providing overviews, and there is a discussion of the boundaries and transitions between interlinear glosses and glossaries, glosses and other insertions of individual words. Further chapters bring together the grammatical and lexical evaluation of glosses, assign glossed manuscripts to their places of composition and provide approaches to a history of glossography. A subject index and index of manuscripts aid navigation through the work, and a comprehensive literature list provides a glossography bibliography.