Densil Morgan declares two main purposes in writing Theologia Cambrensis. First, he aims to shed light on little known Welsh-language texts and show how Welsh Protestants both thought about and conveyed Christian truths to their contemporaries. Second, through contemplation of the past, Morgan hopes to see ‘creative application' to the present in practical theology. His target audience is largely Welsh – the theologians, historians and literary scholars working on early modern Wales, for example – but the book actually has a much wider appeal. It would be invaluable for those who aim to move beyond an anglocentric approach to researching and teaching early modern religious history and theology. As Morgan himself highlights, this is the first work to concentrate explicitly on Welsh theology since 1900, when the Calvinistic Methodist scholar William Evans published An outline of the history of Welsh theology. This century-long lacuna has meant that early modern Welsh religious thought has been unfairly neglected or ignored. For many scholars this will, therefore, represent their first exposure to key Welsh texts and the trends in thought and worship revealed within.

The book is divided into five main chronological chapters, beginning with the translation of the Bible into Welsh and ending with the Methodist Revival. The final two chapters examine (respectively) Anglican piety from 1689 and Nonconformist spirituality in the same period. Happily, given their length (chapter one is seventy-four pages long), these are subdivided further into sensible sections. The structure is, for the most part, very successful. It enables the reader to trace patterns in Welsh theology and church government over the centuries, and it would be difficult to imagine a successful thematic approach that would allow for Morgan's narrative to unravel in this way. That said, either thematic chapter conclusions or an expanded book conclusion would have been able to further develop Morgan's insights into the principal directions and influences on Welsh theology. Morgan has an engaging prose style, providing learned and interesting expositions of Welsh theological works. A particular strength of the book is its contextualisation of the works. When discussing a translated work, attention is paid to the context and authorship of the original. This is then developed in conversation with the Welsh context, and Morgan provides lucid explanations of the importance and influence of his chosen translators and texts. The comparative analysis that forms one of the threads of the book is revealing – particularly in relation to the pace of the Reformation in England and Wales. Morgan demonstrates that in terms of instruction in the Protestant faith the need for, and slow pace of, Welsh translations of key texts (for example the Book of Homilies) meant that they took fifty years longer to arrive. He also shows, however, that the project to evangelise Wales was taken seriously by the English government. Unlike the Irish Church, there was consistent government support for translations of the Bible and the Book of Common Prayer, and the Welsh were portrayed as potential allies rather than religious barbarians.

When discussing the civil wars and interregnum Morgan avoids the previously prevailing tendency to neglect conformist Church of England authors completely in favour of radical Protestant tracts. He constructs a convincing image of a softer, less confrontational Welsh Calvinism which held sway until the rise of radicals such as William Wroth, Walter Cradock and Walter Erbury. He accurately describes the loyalty of the majority of Welshmen to the Prayer Book and episcopalian Church of England, hard won since the sixteenth century, and in the section on 1642–60 discusses episcopalian and Prayer Book divinity as well as the passionate preaching and popular appeal of the radical interregnum preachers. Morgan perhaps overemphasises the continuing impact of such firebrands after their fall, but his descriptions of the impassioned preaching and effervescent writing style of the Welsh radicals is a joy to read. Similarly, in his examination of the Restoration Church and the concomitant situation of the Nonconformists and post-1688 Anglican piety, Morgan is even-handed, an approach that is much more successful in revealing the actions and reactions of the various groupings in the period. He explores the similarities and common ground between Anglicans and dissenters as well as their manifold differences. In a discussion of a period in Welsh history that has, in the past, tended to reveal the personal affiliations and prejudices of writers across the Christian spectrum, the degree of balance is particularly good to see.

Morgan does follow the long-established historiographical trend of blaming poor administration, ecclesiastical government and a conservative society for the slow pace of religious change in sixteenth-century Wales. A failure to enthuse the population with the Protestant message, or indeed an enthusiasm instead for the Catholic faith, is perhaps dismissed with too little engagement. The continuity of a visually rich ecclesiastical built environment, as revealed in the work of Madeleine Gray and Lloyd Bowen, is not explored in great detail. On the other hand, within such a chronologically broad survey text it is difficult to paint other than in broad brush strokes. Within the context of an ambitious project, these are small quibbles. Throughout Theologia Cambrensis Morgan engages the reader with properly contextualised but also theologically learned explanations of the theology and history of Welsh Protestant religion in the period 1588 to 1760. This is an extremely valuable contribution not only to Welsh history, but also to history and theology in a wider British context. I hope that its audience, like some of the religious currents discussed within the book, spreads far beyond the borders of Wales.