Bruce Kaye is one of the most respected of Anglican ecclesiologists. He founded the Journal of Anglican Studies, and his retirement in 2013 was marked by a warm tribute. For many years he worked in English and Australian universities; he was also General Secretary of the Anglican Church of Australia over a lengthy period. He has therefore a breadth of knowledge which is unusual, and which is put to good use in his latest book. Now nearly 80, he reflects on the decline and fall of ‘the English Christendom’. What should the future relationship of Church and State be, given that ‘Christendom’ is now over?

The term ‘Christendom’ is tightly defined, and is taken from Kaye's own reflection on the new edition of Peter Brown's The Rise of Western Christendom: triumph and diversity, ad 200–1000 (2013). What is significant is that Brown rejects the idea of diversity as a failure to reach some ideal of unity. From 400 ad there were only ever a series of micro-Christendoms, each linked in some way to each other. A Christendom is a community with a discernible polity that sees itself as Christian, and within which lay and clerical authority coalesce.

What Kaye is interested in is the existence of this Christendom inside England. His approach to this huge subject is to take four case studies, narrate them with great historical detail and then draw conclusions from each study. The four case studies are England from the Norman Conquest to the thirteenth century; the sixteenth century in England; the United States of America in the late eighteenth century; and nineteenth-century Australia. Kaye therefore studies the great Norman archbishoprics of Lanfranc, Anselm, Becket and Stephen Langton, ending with the truce of the early thirteenth century, but also looking back to Bede. The truce of 1215 gave the power of investiture to the Church, but feudal homage of the Archbishop of Canterbury to his lord, the king. Kaye is excellent in teasing out the different dimensions of this mediaeval struggle, in terms of ecclesiology, jurisprudence and political theory. The compromise lasted until the sixteenth century, when the Reformation destroyed it. There is a paradox here. On the one hand, Henry VIII established an English absolutism that swept away the careful mediaeval tension between Church and State. On the other hand, Richard Hooker, whom Kaye greatly admires, wrote the most subtle justification of Church–State relations in Book VIII of The Lawes of Ecclesiastical Polity. This requires consent for any form of governance, is Christologically aware and relates power to the action of God in the world. Kaye sees it as a magisterial account.

However, neither Henrician absolutism nor Hooker's theoretical justification could prevent the breakdown of the close links between Church and State in the British Empire. The independence of the United States of America was followed by the establishment of Anglican episcopacy but only in terms of episcopacy in relationship to a General Convention, made up of clerical and lay representatives. It was in no sense a ‘Christendom’. A different turn of events took place in the Australian colonies in the nineteenth century which led to a much more decentralised ecclesiology, but again with very loose Church–State relations, and diocesan synods alongside episcopacy. Again, English Christendom ended in the Australian colonies.

So, what is the future today? The last 30 pages attempt to give an answer. In one way I found this section marked by a change in tone, and I wonder whether Kaye did not find drawing his book together an easy task. Partly the last 30 pages of this 300-page study draw out the threads that have run through all the historical studies. Lay sovereignty of the monarch, co-operation between Church and State, the sense of a shared mission, national unity and the sacred canopy (divine legitimisation of authority) were all marks of the English Christendom. All this is well said, and very illuminating. Kaye then turns to those who oppose the idea of Christendom at all, in particular the contemporary United States theologians Alan Kreider and Stanley Hauerwas.

The final 15 pages are especially ambiguous. Kreider and Hauerwas write about the need to train disciples and build communities in a world that is post-Christendom. Yet, having said this, Kaye turns back and reflects on the values that the historical case studies have shown: order, power unity and catholicity. (There is a mistake on page 293: ‘The Conventional Act of 1664’ should read ‘The Conventicle Act’.) Furthermore J C D Clark in English Society 1660–1832 would dispute that English Christendom ended in 1662 with the expulsion of clergy who would not accept the Prayer Book and episcopal ordination. Clark offers a different account of English eighteenth-century society as a confessional state in which law and religion intertwined, and the role of the Church of England was entirely bound up with social order, politics and culture (English Society, pp 29 and 38). Had Kaye accepted that ‘Christendom’ can mean a cultural unity held together by a hegemony of Church and State, he would have seen that Clark was correct in seeing the end of English Christendom as being as late as the 1830s. Furthermore, historians such as Matthew Grimley have written much on twentieth-century intertwining of British national identity and religion, especially with the Church of England. There are many writers, such as Paul Avis or Mark Chapman, who would not write off the established church in England quite as quickly as Kaye does.

The great value of Kaye's book is a detailed account of English Christendom, with acute theological reflection on the case studies. It is wonderful to have such a thoughtful account, especially when extended to Australia and the United States. The last chapter is, however, problematic. Was there a failure of nerve there? Nevertheless, this is an outstanding survey from one of the leading theologians in the Anglican Communion.