Traditionally, Irish religious historians tended to stick to their own parish. From the reformation right through to the twentieth century, Protestant historians focused upon the Protestant churches, Catholic ones on the Catholic church. A host of developments from the 1960s onwards—ecumenism, the secularization of Irish society and universities, the internationalization and diversification of Irish historical studies—have transformed the discipline. What was formerly one-eyed ecclesiastical history is now a broad-ranging and methodologically diverse study of Irish religion. There is, perhaps, no better example of this transformation than the work of Tadhg Ó hAnnracháin, currently a professor in the History Department at University College Dublin. From the very start of his career he broke with traditional molds, not following the usual path of UCD history graduates to Cambridge but pursuing his doctoral studies at the European University Institute in Florence. His first publication—the “book of the thesis”—Catholic Reformation in Ireland: The Mission of Rinuccini 1645–1649 (Oxford University Press, 2002), was original and groundbreaking, both in its use of European sources to understand the mind of Rinuccini and in its revision of accepted ideas about the reception of the eformation amongst the ethnic communities in Ireland. Since then, he has run a major research project on “Celtic” Christianities, and published a survey of the broader European Counter-Reformation, not from the perspective of the center, as is usual, but from the peripheries.

Now, in Confessionalism and Mobility, true to form, he offers us another work which is groundbreaking, first in its methodology, of applying the insights into the importance of mobility gained from anthropology and sociology and applying them to Irish religion; second in its radical determination to tackle the whole of Irish religion, Protestant and Catholic, giving rise to a slew of new comparative insights; and finally, in its unusual and highly-productive timeframe, stretching across the period 1580 to 1685, when the modern religious configuration of Irish society was established.

The organizing concept disdains “sedentarist metaphysics” and its assumption that people and social orders are largely static, and instead focuses upon the dynamic effects of mobility in shaping societies—it is estimated that 100 million people crossed European state boundaries in the period of 1550–1800. Given that the growing scholarship on early-modern European mobility has paid little attention to the interaction between such movement and the enormous religious changes of the Reformation and Counter-Reformation, and that Irish interest in mobility has been limited to relatively traditional studies of colonization and settlement, Ó hAnnracháin's choice of topic is doubly innovative.

His case is that mobility in Ireland—whether localized as in, for example, the increasing intermarriage between native Irish and Old English families; journeys to mass or to holy wells; transnational, as in the case of English and Scottish settlers moving to Ireland; or Irish mercenaries serving in European armies—was either overtly religious or had an important religious dimension. Mobility was therefore, he argues, “a fundamental constitutive process in the religious transformation of ideas, practices, and identities that took place in Ireland during this crucial time period, which in turn had enormous ramifications for the political and economic development of the kingdom” (4). Indeed, only in the Netherlands did mobility have a similarly significant impact on religious developments.

The first part of the book examines confessional mobility, most especially the transnational aspects of clerical formation—Catholic priests in mainland Europe, Church of Ireland clergy in Oxford and Cambridge (despite the contribution of Trinity College Dublin), and Presbyterian ministers in Scotland. The second part of the book takes a more thematic approach, starting with a quirky chapter on spiritual metaphors of mobility—walking with God, desert wandering, and promised-land arrivals—in Protestant and Catholic religious writings, then moving on to the “practices of religious mobility,” in effect looking not at the rites and ceremonies of the churches but at the process of getting to and gathering for these services, and then the distinctive denominational practices—such as Catholic pilgrimages and Presbyterian interparochial communions—which shaped the development of these communities. Chapters 8 and 9 provide the intellectual heart of the book: First, detailed analyses of key Catholic texts to show the interplay between religious identity and what Ó hAnnracháin calls exilic consciousness; then, two Church of Ireland works—including the totemic History of the Rebellion (London, 1646) by Sir John Temple; and finally, Andrew Stewart's history of the Presbyterians in Ireland.

In conclusion, it is difficult in this relatively short review to do justice to the innovative and mold-breaking approach of this book and the fresh insights that Tadhg Ó hAnnracháin offers us on early-modern Irish—and European—religious developments through the prism of mobility. Though there is, of course, one simple way of resolving that difficulty—go and read this book for yourself!