Frankly I found this book disappointing. Leo is a vastly important subject both for fifth-century Rome and more broadly for the Church in the later empire and the relations of the west to one of the hottest periods of fifth-century Christological and ecumenical controversy. The book covers the ground solidly with useful chapters on a series of topics: the historical frame in the introduction and specifically on Rome and the western Churches; key aspects of Leo's own theological contributions in the idea of justice and its bearing upon law and mercy, the theology of poverty, charity and altruism, and the humanity of Christ as a model for compassion; and the problems of the councils – overturning the Robber Synod, the elaboration of Roman primacy and the search for unity after Chalcedon. The book ends with a post-Augustine chapter on how the ‘City of God’ unfolds in history. All of this is useful, sensible, up-to-date; the learning appears to be fine. But the book makes no compelling case to one with an interest but not a systematic expertise in this period to pursue it further. It does not bring Leo or his thought to life. It does not sufficiently place him – or indeed the Roman Church – in creative contrast with or conceptual tension against some of the great figures of the period, such as his earlier contemporaries like John Cassian and Augustine in the west, let alone the likes of Nestorius and Cyril in the east.