This book significantly expands our understanding of the life and work of Polycarp of Smyrna. Part One establishes that the anonymous "apostolic presbyterquot;, whose oral teaching is cited intermittently by Irenaeus in Against Heresies 4.27.1 through 4.32.1, is in fact Polycarp. The fragments of teaching preserved by Irenaeus shed valuable light upon his relationship with Polycarp, establishing that Irenaeus' contact with his teacher was neither fleeting nor shallow. They also reveal Polycarp's important role in opposing the early effects of the Marcionite movement and gain a valuable perspective on Polycarp's Old Testament hermeneutic in the face of ecclesiastical controversy. Part Two considers the many links which would tie Polycarp to the work known as Ad Diognetum. Charles E. Hill proposes that the work is not a treatise but the transcript of an oral address. A new proposal is made for the identity of Diognetus, the addressee, based upon archaeological evidence of an aristocratic Smyrnaean family of the second century.