The present study provides for the first time a systematic and comprehensive examination of the evidence for ecclesiastical penance found in the vast corpus of pre-Metaphrastic Byzantine hagiography. The value of the thesis lies primarily in the body of evidence which it makes available and interprets within the context of what can be known of the historical development of penitential practice among the Byzantine laity and of the nature and limitations of hagiographical evidence. The evidence is arranged chronologically in four sections (330-551, 451-692, 692-863, 843-983), and a distinction is made within each section between evidence which reflects a Constantinopolitan milieu and evidence taken from other areas of the Greek-speaking Christian world. The cumulative weight of the evidence supports the following conclusions about the history of Byzantine penance: 1) ecclesiastical penance did not cease to exist in the Byzantine churches following the "Nectarius incident" of 391/2; 2) monastic influence upon the outward form and inner understanding of ecclesiastical penance spread gradually from the fourth century onwards and was not a sudden phenomenon provoked by the events of the iconoclastic age; 3) the constitutive elements of the modern Greek practice of confession can be found in the practice of Byzantine lay people already in the fifth and sixth centuries, but the Lives of the saints nowhere suggest that confession was ever an obligation upon the laity in the period under survey or that a majority of the Byzantine faithful had recourse to the institutions of ecclesiastical'penance as a normal or routine part of their religious practice; 4) the phenomenon of unordained monks consciously exercising the apostolic power of binding and loosing was not, as Holl asserted, a central and informing element in the history of Byzantine penitential practice; 5) enthusiasm for hagiographical sources as privileged reflectors of the Byzantine popular milieu must be tempered by a realistic appreciation of the limitations inherent in the narrative forms and techniques of hagiography.