This open access book provides the first full-length exploration of guide dogs in medieval textual and artistic sources. It is sometimes suggested that guide dogs did not exist during the medieval period, and most of the research that does recognise their existence does so using a small set of examples. This book reveals new information about disability in the premodern world by introducing and analysing a corpus of images and textual references to guide dogs, all of which appear in manuscripts created during the late medieval period (here defined as 1100-1500) in the specific areas under investigation (France, the British Isles, Belgium, and The Netherlands). Exploring this evidence using both quantitative and qualitative approaches, which is the goal of this study, is important, because the history of guide dogs and their representations is directly relevant to several present-day social issues and to the growing field of Disability Studies. Krista A. Milne is Universitair docent at Leiden University, in The Netherlands, where she researches and teaches medieval literature and book culture. She has written two other books: The Destruction of Medieval Manuscripts in England: Institutional Collections (2025) and Manuals for Penitents in Medieval England: From 'Ancrene Wisse' to 'The Parson's Tale' (2021). Her grant-funded projects include an investigation into medieval guide dogs (2024 Dutch Research Council Open Competition XS Grant) that, along with her previous work in the field of Disability Studies, inspired this book.