What does it mean to be authentic? The term is as pervasive today as it is difficult to define. To be 'authentic' in the Middle Ages or Early Modernity was no less of a complex task, albeit framed in ways different to today's concept of authenticity as an individualistic or capitalistic venture (think 'being true to oneself' or 'brand authenticity'). This volume examines a range of medieval and early modern approaches to authenticity in literature, asking how authenticity was defined, privileged, constructed, and contested in the periods covered. Essays trace the shifting status of authenticity across four literary categories which most test the concept of premodern authenticity: forgeries, histories, translations, and continuations. Contributions engage with works across Latin, Greek, English, French, and Irish, and set authenticity in conversation with medieval and modern perspectives on authority, truth, and morality.