Theodosius isn't a particularly fashionable emperor. Sometimes seen as the unwitting architect of the fall of the Western Empire, he is often shunned as a topic of serious academic discussion, often only gaining a guest starring role in histories of the Early Church or the emergence of the Eastern Empire. This is by and large a missed opportunity, Theodosius reign provides a lot of scope for insight into key themes in later Roman History such as Rome's relationship with the Goths, religious unrest and the East/West divide. Williams and Friell, provide a useful account of Theodosius reign, drawing on literary, archaeological, epigraphical and numismatic evidence.
The work is primarily a biography. It starts prior to Theodosius with a brief build up to Adrianople, whilst the work then carries on with a good chapter on Stilicho and a discussion as to whether the East/West split was inevitable. The authors know their source material well and this is evident in how they structure the chapters and also in how the use Gibbon, who centuries later still, looms large in this subject area.
The work is largely a defence of Theodosius, setting his reign between two key historical turning points, the battle of Adrianople, which destabilised the East and his early death, which left his two young sons nominally in charge of the Empire. Such a revision is welcome in helping to rebalance the historical scales, though at times it can feel, that the work defers too much toward absolving Theodosius; he certainly made mistakes (hereditary rule for his sons, was an example, especially given his non-hereditary elevation by Gratian) and it is possible to tackle both his indecision and inconsistency (such as volte-face regarding pagan worship in the Empire). However this must be set against the works wider emphasis which is to challenge some misconceptions about the Later Roman Empire that have persisted since Gibbon, in particularly the chapters on the barbarisation of the army and on religion are good reads in this respect.
I'd recommend this to anyone interested in the Later Empire and also with an interest in Rome's relationship with Barbarians.