A monograph on the monasticism of fifth- and sixth-century Gaza has been a desideratum of scholarship for some time and this book (which is based on research made easier by the publication, between 1997 and 2002, of a new edition of the letters or Questions and answers of Barsanuphius and John in the series Sources Chrétiennes) fulfils the requirement without closing the door on future research which may find more to say. Chapters i and ii, a historical introduction, contain little that will be new to readers familiar, even in outline, with the study of Palestinian monasticism and its hagiographical sources. They concern a cast of well-known characters including Abba Isaiah, Barsanuphius and John, and above all Peter the Iberian, the leader of anti-Chalcedonian monasticism in Palestine, whose portrayal in his Life by John Rufus as the image of the biblical Moses is discussed separately in chapter iii. In chapter iv the focus shifts to Barsanuphius and John, with a summary of their ministry to monks and lay people, status as charismatic figures and negative attitudes to theological speculation. In chapters v–viii sin and the struggle against temptation, penitence (including the theologically-important phenomenon of penance shared by an abba and disciple) and prayer are the topics discussed. The authors conclude – not very surprisingly – that the two Old Men's teaching on prayer was a synthesis of Evagrian concepts and other, less intellectual elements (p. 182). In chapter ix food, sleep, medicine, work and other aspects of daily life are considered, and in chapter x social interactions including the tension within the monastic life between the desire for solitude and commitment to a community (a subject returned to in the brief conclusion at pp. 224–5), relations between abba and disciple, and attitudes to visitors and outsiders. Throughout these chapters the views of Barsanuphius and John are contextualised with reference to earlier monastic sources, including Isaiah's Asceticon, Basil of Caesarea's writings and the Pachomian literature. The final chapter suggests that the monastery of Abba Seridos, to which the Old Men acted as guides, was, despite outward conformity to Chalcedon, crypto-Monophysite in belief – a view for which, the authors admit, there is only later and inconclusive evidence. There are one or two errors of translation – for example pp. 92 (letter 305) and 173, where ‘luxury’ (translating pornei/a) is a misleading calque of the French ‘luxure’. Chapter v includes some speculations about letter 137b which appear, despite disclaimers (pp. 120, 124), to be intended to make out that Barsanuphius participated in a quasi-Gnostic alphabetic mysticism – and to interpret the saying Arsenius 6 in the Apophthegmata patrum in this light (p. 110) is very implausible. Generally, however, this is a sound and sympathetic if summary interpretation of the spirituality of a somewhat neglected phase in the history of monasticism.