After Augustus

Almost every emperor had to deal with internal and external enemies, whether it was thrust upon them or not. Moreover, the army was an entity that an emperor simply could not ignore. How the various dealt with it, however, differed greatly. Some emperors evidently were more interested in military matters than others and took it upon themselves to alter the army in some way. Tactics, size, hierarchy, equipment and conditions of service were all adapted to changing circumstances at varying moments in the Principate. And although it is often hard to pinpoint the instant, or even the reign, when such a change was carried through or who initiated a new development, the emperors were often involved. The armed forces were too important to be left alone. That is not to say that the emperor was involved in every aspect of every reform. Innovative local commanders, influences from outside the empire and experimentation on lower levels could, for instance, lead to changes in tactics or equipment. There is no doubt however that the emperor, or his representatives, were involved where it concerned organization, appointment, deployment and conditions of service.