This book is a most interesting study of a medieval mystic woman in that it discusses her primarily, indeed almost exclusively, in her contemporary political and historical context. Although visions and ecstacies are mentioned in passing the details of Siennese and Florentine relations with the papacy in Avignon are really the focus of this book. We learn much about the political affiliations of the young noblemen and others who formed Catherine's ‘family’ and her journeys are mapped onto the political crises of the time. This provides the convincing context of the book's thesis – that Catherine of Siena was an agent of the pope and that her letters should be read as political as well as spiritual messages. The historical implication is clearly that Florence's commitment to republicanism was a religious problem and not merely a secular ideology as it is sometimes represented. Interesting too is the way Luongo charts the increasing authority in Catherine's letters even to the pope himself. The wider context of the book is of course Catherine of Siena as a medieval mystic – but a reader looking for a discussion of her significance as a spiritual leader or mystic theologian will be disappointed. On the other hand this book provides a welcome counterblast to the prevalent tendency to view these fascinating women as somehow hermetically sealed off from the rest of their society. Although there is less evidence in the case of most other medieval women mystics (with the obvious exception of Hildegard of Bingen) this book is a salutary reminder that spiritual gifts could be, and were, used to influence and rule. These were intelligent women from influential familes who were accustomed to see power used expertly – for them not to exercise their own power in similar ways would have been unthinkable. We are too often guilty of naivety when we take these women's protestations of illiteracy and weakness at face value rather than appreciating them for what they were – powerful weapons skilfully used. I would recommend this book to all those interested in medieval women – not just those interested in Catherine of Siena – as an example of how such women could wield their power. Not all of them did so as prominently on the world stage as Catherine did, but we do them less than justice if we forget that they will all have done so to some extent.