Jacques Paul Migne’s Patrologiae Cursus Completus: Series Graeca forms the largest collection ever published of the extant writings of the Greek Fathers and Doctors of the early and medieval Church. It served as the translation base for Philip Schaff’s Early Church Fathers and has been the bedrock for theological and historical studies of the time period extending from the Apostolic Fathers in the late first or early second century to the fifteenth century.