“War is the father of all things”, as the wise old Greek said. 1 The process of urbanization in Roman Italy is a good illustration of the truth of this saying. The distinctive political, economic and social structures that characterized It Italy under Roman rule were brought about by war. In so far as they were the product of conscious or deliberate planning, they had an exclusively warlike function. The facts are elementary and familiar, but we need constantly to remind ourselves of them because they are all too easily overlooked. For instance, when considering the sophisticated and cultured life of Pompeii in AD 79, and the secure and comfortable existence of its leisured class, not everyone remembers that at the same time a Roman army under Julius Agricola was engaged in a destructive and bloody campaign in northern Britain—making a desert and calling it peace, in Tacitus’ immortal words. It is difficult at first sight to see any connection between these two worlds; and indeed one of the most striking things about the Roman principate is the huge gap that separated the civilian society of Italy and the inner provinces from the military life which was exclusively confined to remote frontier provinces. The demilitarization of Italy and the creation of a civilian society separated from warfare and military matters not only by geographical space but also in people’s experience and outlook, are amongst the most striking consequences of the profound social transformation that we call the Roman revolution. 2