Matteo Caponi's Una Chiesa in guerra is a micro-historical work on the role of the Florentine diocese during the years surrounding the First World War. Specifically, it demonstrates, with reference to this locality, the intersectional processes of religion, nationalism, and wartime mobilisation from a strongly culturalist perspective. The book is divided into five chapters, each containing five to eight sections, as well as an introductory and concluding section. It is highly readable and well organised, offering a detailed portrayal of the complex networks of the Florentine diocese and their extensive impact in both local and national arenas. Furthermore, this book well justifies its challenging stance in the context of the surrounding historiographical literature, dealing, in particular, with the treatment of the Church's relationship with right-wing movements.

Caponi looks in detail at the continuing fashions in historiography concerning Italian faith and the First World War. Questioning the common historiographical position of ‘the religion of war’, Caponi elects to focus on the Florentine diocese in order to more accurately depict the concrete mechanisms by which ecclesiastical institutions and faith contributed to the rhetorical construction of patriotic sacrifice. Utilising micro-historical methodology, Caponi aims to demonstrate manifestations of this process in the Florentine context, both in connection and in parallel with that on the macro-national level. Caponi chooses Florence on which to base this study, due to its highly unique municipal features, including its discernible intellectual fertility, even within the framework of the Catholic Church.

Among the highlights of Caponi's achievement is his presentation of the aggrandisement of the role of ecclesiasts in the war effort, from their initial function in offering pastoral support to their eventual participation as soldiers and policy-makers. Caponi also examines the role and delineation of ‘consensus’ in the context of national belligerency, utilising sources varying from private letters to popular religious literature and war memorials. He also highlights the role and treatment of women in this historical process, a subject often overshadowed in the traditional literature. Caponi's method ensures the preservation of a broad-based perspective within a highly focused approach, consistently offering comparative perspectives between cases in Florence and other Italian municipalities.

Despite its exceptionally strong attention to detail, the book could be criticised for its lack of justification of its focus upon, specifically, the Catholic Church, as during this time in Florence, there were sizable minority communities of Jews and Anglicans who also participated in Florence's Great War efforts, as featured in the work of Christina Loong. Supplementary comments on their involvement in connection to that of Florence's Catholic diocese would further strengthen Caponi's innovative stance of raising questions central to the religious history of the First World War in tandem with seeking to discover its ‘transnational moment’.

Nevertheless, the greatest contribution of this piece is its excavation of the nuances of the Florentine diocese's role in the political, cultural, and social reaction of the Great War as well as their trans-scalar impacts. Dispensing with the traditionally portrayed ‘totalisation’ of the First World War, Caponi expertly draws on a full gamut of ecclesiastical perspectives, uncovering the multiple facets of this subject, too often flatly portrayed. In addition, he fully illustrates the significance of this research in a far broader temporal plane. Turning to the present day, Caponi states that in the context of the centenary of the First World War, the modern Catholic Church has often suppressed narratives of its nationalistic belligerent tendencies, in favour of a strongly globalised pacifism; over the century the church has moved from a position of ‘We [Italians] are with God’ to a position of ‘[A peace-loving] God is with us [i.e. with all Catholics]’, spotlighting the need to explore the historical process of the Church's ‘evangelicalisation of its age’.

Whilst this book is strongly directed towards scholars of early twentieth-century Italian Church history, it also contains much material that would be of interest to cultural historians of early twentieth-century Italy, particularly those who examine political spiritualism. In addition, this work nicely parallels research on Fascism, particularly that focused on a scalar analysis of the utilisation of the Church to legitimise and integrate the Fascist state. For historians outside these fields, Caponi's work is a well-crafted model of thorough micro-history.