Why are contemporary readers so fascinated by retellings of the Iliad or Beowulf? And why have retellings of premodern – ancient and medieval – texts not been taken seriously as a literary practice to date? In DERIVATE, I investigate the striking surge of retellings in contemporary English literature by setting the contemporary texts in a productive dialogue with practices of writing in the Middle Ages. The medieval period offers a perfect point of departure for theorizing retellings as medieval literature was inherently derivative and medieval authors had developed a system for being inventive within a system of derivations. Taking issue with the privileging of that which is new in literary history, I propose a new paradigm for literary history: literary history as a history of derivations. Starting from the premise that retelling is a transhistorical concept, the project sheds new light on the processes of reception that find their expression in the current interest in and relevance of premodern material. The project triangulates (classical) reception studies, medieval literary studies as well as literary theory, especially postmodernist theory, and scrutinizes the practice of retelling premodern (ancient and medieval) texts in contemporary English literature. DERIVATE thus develops a theory of retelling based on the intense engagement and critical comparison with medieval practices of retelling in order to map the wider cultural, historical, and literary contexts and implications of the current trend in retellings of classical and medieval texts (audiences, canon, literary market) as a springboard for developing a literary history of derivations.