The first command task involved control as well as decentralisation. Chapter explains the military organisation which exerted control and implemented the two further traditional principles involved, establishing a point of main effort (Schwerpunkt) and maintaining the chain of command. Describes the roles of the four levels of command covered by the book, army groups, Armies, corps and divisions, focusing on often-misunderstood changes brought about by the strain of modern battle.

Case study illustrates the difficulties and successes of implementing the Schwerpunkt and chain of command principles as the German army prepared for the Entente offensive. Concluding section links organisational change in 1917 to pre-war thinking on command and stresses the difficulty of striking the right balance between the two elements of the first command task, decentralisation and control. Outcome depended on the complex interplay of principles, formal organisational responsibilities, events and in particular personal factors.

The overall approach of the book is thematic, with the Introduction providing important context for what follows, especially for those less familiar with Roman history, first by defining key terms and parameters (especially explaining the chronological range of the volume, from the fourth century BC to the early seventh century AD), and then through an overview of the incidence of warfare, both external and internal, across the course of Roman history. The evolution of Roman military forces from the Republic through to Late Antiquity is outlined, with particular attention to Augustus’ formalisation of a standing army and the reconfiguration of the empire’s forces in the early fourth century. Finally, the most important ancient sources for the subject are introduced, with discussion of key literary sources (Polybius, Caesar, Livy, Josephus, Tacitus, Ammianus Marcellinus and Procopius), the less familiar Syriac chronicle atttributed to Joshua the Stylite, military treatises, documentary evidence (inscriptions, papyri) and relevant archaeological material.