The marginalia of Thomas Swalwell (d. 1539) in his many early printed books provide remarkable access to the interests and concerns of a typical late medieval English Benedictine monk. Devout, scholarly, and busy, he studies everything from how to assess tithes on sheep to theological differences between Muslims and Christians. He is passionate about prayer, preaching, and clerical integrity, while carrying significant administrative responsibilities within the Durham Priory. In the early years of the Reformation, his annotations reveal the impact of religious change and his response to it. Illustrated with samples of Swalwell's marginalia and rare sheets of his manuscript notes, this volume will be a welcome addition to the collection of anyone interested in monasticism, the history of the book, or early English Reformation history.