The canons and canonesses of St Augustine, in their various guises, were the most widespread of all of the religious orders in medieval Ireland. Their influence on people in Ireland from the twelfth century through to the dissolution of their houses by the English/British crown from the 1530s, and for decades afterwards, was significant in myriad ways. Yet, with the death of the last Irish Augustinian canon in 1829 their story was neglected until Sarah Preston's pioneering study in 1996, and the Fourth Glenstal History Conference in 2017 provided the impetus for a multidisciplinary research initiative of which this book is the fruit. Edel Bhreathnach sets the scene by challenging the ‘insularity’ of earlier scholars who considered the origins and early development of the Augustinian canons in Ireland. She presents a forensic analysis of the nature of the canons and shows that ‘there was no standard rule of Augustine’ anywhere in Christendom, but a very great deal of regional diversity and debates that persisted for centuries.

This comparative approach allows Bhreathnach to argue that the Irish church before the Norman invasion was not unique as scholars have long supposed: it shared with other churches of the time genuine coenobitic traditions, a clergy with a pastoral remit and subject to bishops, an embryonic episcopal structure and possibly communities of priests in major churches, a scholarly community versed in ecclesiastical and secular learning, and a hugely powerful elite who managed the church's economic resources. She offers a number of case studies to show how some Augustinian canons and canonesses were introduced into Ireland by reforming bishops, kings and noble men and women and how they interacted with the existing church. However, she warns against making premature generalisations before ‘far more detailed archaeological and architectural studies’ are carried out to help compensate for the lack of documentary evidence for a great many sites. Bhreathnach modestly concludes that she has raised more questions than she has answered but she has, in fact, offered a very satisfying starting point for future research.

Three overlapping chapters dovetail neatly with Bhreathnach's agenda. Rachel Moss's survey of the material culture of the canonical movement, Pádraig Ó Riain's survey of the canons’ contribution to Irish hagiography and Louise Nugent's study of the canons’ role in the development of late medieval Irish pilgrimage set the Augustinians’ endeavours in Ireland in their wider European context to explicate what they were trying to achieve. Colmán Ó Clabaigh brings his own experiences as a Benedictine to bear in using the chapter books and necrologies that have survived from Dublin and Trim to give the reader a sympathetic impression of the mentalité and inner working of two Augustinian communities. Marie Therese Flanagan and Miriam Clyne present studies of the Victorine canons and the canons of Prémontré in Ireland respectively. Both succeed in elucidating their subjects in impressive detail. Flanagan's study is based on a richer seam of documentation, but Clyne's chapter is greatly enriched by her use of archaeological and architectural evidence from the priory at Lough Key to transcend the comparatively scant documentary records at her disposal.

Tracy Collins presents a ground-breaking account of the archaeology of Augustinian nuns in the middle ages. Her focus is on enclosed communities and, hence, she discusses nuns rather than canonesses in her chapter, though she observes that no Irish nunnery has any trace of an enclosing wall. Of the sixty-five nunneries known from late medieval Ireland physical evidence survives from thirty of them, all of them Augustinian, and this points to general multiformity in design. Ten or eleven of the nunneries were co-located with the houses of male Augustinians. Her map on (p. 29) shows some interesting clusters of nunneries, as in the vicinity of Clonfert, and begs the question as to whether the clusters identified were simply random phenomena or whether there were many more nunneries in existence than those mentioned in the patchy records that have chanced to survive.

Tadhg O'Keefe's study of the eight known transeptal churches of the regular canons in Ireland shows that all but one of them date from the early years of the English invasion, between 1177 and 1210, with the exception at Ballintubber — the only example built in an area that was not conquered. The discussion of the architecture of the priories at Athassel, County Tipperary, Ballybogan, County Dublin and Newtown Trim, County Meath, exemplify what can be achieved by a maestro in his field. O'Keefe suggests that the transeptal church was a manifestation of the ‘big bang’ of Augustinian monastic culture after 1177 and as such must have implications for our understanding of the nature of the Augustinian regular community before the invasion. The association of some Augustinian communities with English colonisation in eastern Ireland is analysed in depth by Arlene Hogan through her study of the cartularies of the canons of Llanthony Prima and Secunda. Adrian Empey emphasises the Augustinian contribution to the development of the parochial system across much of Ireland from the twelfth century. However, this reviewer suspects that their role was more parasitic than positive.

Finally, Brendan Scott addresses the dissolution of the Augustinian houses in the Pale by Henry VIII, while Clemens Galban surveys the story of the Augustinians in Ireland following the Henrician dissolutions until their eventual extinction with the death of the last abbot in 1829. Altogether this impressive collection of essays transforms our understanding and appreciation of one of the largest institutions in operation in medieval Ireland. It shows how much Ireland's rich built heritage can contribute to the study of Irish history, and it reminds any historian who may yet need to be reminded of the pitfalls of insularity when studying the transnational medieval Church.