A major change in Roman military policy appears to have occurred at the end of the reign of Augustus. Until then the empire had grown inexorably as a result of centuries of successful war. The conquest of Italy in the fourth and third centuries BC was followed by a series of major wars during the last two centuries of the Republic in Spain, North Africa, Greece, Asia Minor, Syria and continental Gaul, which resulted in the formation of a far-flung territorial empire directly controlled from Rome. The process of expansion continued under Augustus, whose armies overran Egypt, north-west Spain, the Alps, parts of Austria and most of the Balkans. An attempt to conquer Germany and to extend the Roman frontier to the Elbe had to be abandoned in AD 9, however, and the armies were brought back to the Rhine. By the end of his reign, Augustus had evidently decided against further expansion; on his deathbed, we are told, he instructed his heir to keep the empire within its existing borders.1