Ademar of Chabannes (c. 989–1033/4) is primarily known as one of the main contemporary chroniclers of early Capetian France. But he was, as Daniel Callahan shows, much more than that. He was also a scribe, gifted illustrator, musician and liturgist, theologian and shameless propagandist for the alleged apostolic status of St Martial, the patron of his monastery at Limoges. And in all his varied work Jerusalem, both the actual city to which he set off on pilgrimage in the millennial year of 1033 and where he subsequently died, and the imagined heavenly Jerusalem, played a crucial role. Callahan demonstrates the centrality of Jerusalem to his thought from, in particular, his writings in two unpublished manuscripts: BN, ms Lat. 2469, containing forty-six of his sermons, many of them devoted to St Martial, and Deutsche Staatsbibliothek, Berlin, ms Phillip 1664, in which a number of theological works by Bede, Jerome and Theodulf of Orleans, copied, interpolated and glossed by Ademar, are interspersed with his own writings, and various miscellaneous material that he had collected (and in at least one case forged) relating to the Cross and the Holy City. In all these writings Ademar stressed the significance of the Cross in his theology of the Incarnation, and vaunted the claims of Limoges to be a second Jerusalem. The second theme which Callahan stresses is the Apocalypse, for Ademar was also intimately concerned with the imminent coming of the AntiChrist – a product especially of his reflections on the Book of Daniel, and of Bede's commentary on Revelation – portions of which were copied in ms 1664. The emergence of heretics in his own time, whom Ademar considered to be Manicheans, and the destruction of the Holy Sepulchre by al-Hakim (whom Ademar identified with Nebuchadnezzar), concentrated his mind on the appearance of the AntiChrist – if al-Hakim was not indeed he – and the end of time. And at the Last Judgement St Martial would have an honoured place before Christ, interceding for the Christians of Aquitaine.

This is a rich and deeply learned book, locating Ademar's writings within the broader context of early medieval thought, and in comparison to his contemporaries such as Radulf Glaber. The significance of Jerusalem to clerical intellectuals in the century before the First Crusade is made abundantly clear. Probably the most controversial part of this book is Callahan's insistence, which he has already put forward in a number of previous writings, that the heretics who appeared in southern France in the early eleventh century really were dualists, and indeed Bogomils (contra Robert Moore and others). That claim may well be greeted with scepticism. But we should nevertheless welcome this thoughtful and deeply-learned study as the culmination of a lifetime's work on Ademar and monastic life in early medieval Aquitaine.