Donald Prudlo holds the Warren Chair of Catholic Studies at the University of Tulsa. He is the author of Certain Sainthood: The Origins of Papal Infallibility in Canonization, The Martyred Inquisitor: The Life and Cult of Peter of Verona (†1252), Thomas Aquinas: A Historical, Theological, and Environmental Portrait, and several edited volumes, in addition to many articles and chapters on such topics as hagiography, historical theology, and Church history.