This is the first full-length study of Demetrius of Alexandria (189-232 ce), who generated a neglected, yet remarkable hagiographic program that secured him a positive legacy throughout the Middle Ages and the modern era. Drawing upon Patristic, Coptic, and Arabic sources spanning a millennium, the analysis contextualizes the Demetrian corpus at its various stages of composition and presents the totality of his hagiographic corpus in translation. This volume constitutes a definitive study of Demetrius, but more broadly, it provides a clearly delineated hagiographic program and charts its evolution against a backdrop of political developments and intercommunal interactions. This fascinating study is a useful resource for students of Demetrius and the Church in Egypt in this period, but also for anyone working on Early Christianity and hagiography more generally.