The Roman emperor did not exist. Of course, for most of the time from about 50 BC to 1453 there was a man in Rome, and later Constantinople, who for all intents and purposes ruled the empire and was named Augustus. But the expectations of what that man should be and do differed wildly. Various people in various contexts at various times knew exactly what to expect of their emperor. Yet these people did not necessarily agree with one another. That there were such different expectations mattered. It influenced the way in which emperors were depicted and described, the way in which they were remembered, the people with whom they were surrounded, and even how they acted. Context created emperorship. Different groups and individuals tried to understand and formulate the supreme position of the Roman emperor, and then adapt these formulations to changing contexts. They had to, as emperorship as such was never decidedly defined.

The Roman imperial entourage was central to Roman rule. It changed over time. Certain roles became more defined, and certain types of behaviour less contested. It is doubtful whether this was an ‘institutionalisation’ of the Roman court. The entourage of Roman emperors never quite grew into a stable structure. Even the composition of the supposedly formalised administration of the late-Roman eastern empire fluctuated from one reign to the next. Over time, a wider range of types of behaviour became acceptable. Changes in society altered the composition of the people who had the emperor’s ear. The increased militarisation of Roman society in the third century and the emperor’s absence from Rome, had an impact on the emperor’s entourage. Noticeable was the way imperial women wielded independent power in a Christianised empire. The move away from Rome as imperial capital changed the position of senators at court. When comparing the composition and behaviour of people who were regularly in the emperor’s proximity at the beginning of the principate and in the middle of the sixth century, there were substantial differences.

The Roman emperor ruled one of the largest empires in world history. It consisted of different peoples living in wildly different contexts. They had different expectations of who the emperor was and how he should behave, although the range of those expectations was limited. Views of emperorship were locally dependent. The image of the emperor was not the same throughout the empire, and was often closely bound to his visibility in and his relationship with a specific region. How emperors were represented through statues, historical reliefs, triumphal arches, temples and other monuments, and through the ceremonies that surrounded emperorship, had an enormous impact on how the people who encountered these monuments or participated in these ceremonies perceived their emperors. As the number of monuments accumulated over time, they created an increasingly stable local ‘memoryscape’. Existing imagery influenced both the creation of new local images and the expectations of imperial behaviour.

This introductions sets out the key notions underlying a systematic analysis of Roman emperorship over six centuries. It focuses on the sources available for such an analysis and the pitfals in using them. Much attention is paid to the way Roman emperors were remembered, and how these expectations influenced the actions of later emperors.

In many ways, the development of the image of Roman emperors was a search for a way to make the supreme position of the emperor recognisable in an acceptable way, through tools that were already available. Emperorship was never unambiguously defined, other than by the name Augustus. Over time, the range of options which emperors and the inhabitants of the empire had to portray the ruler extended as previously less acceptable modes of representation became normalised. At the same time, there was some sort of congruence in what were typical imperial attributes. The much-discussed ceremonial reforms of Diocletian were a confirmation of practice, rather than a watershed. They did not end the variety of imagery. Expectations of how emperors ought to be described and portrayed continued to differ regionally, medially and between social groups, even when typically imperial modes of representation, with diadem, purple cloak and standardised facial features solidified. Very few typically imperial features, the diadem excepted, were unique to the emperor. For many people, the Roman emperor would always remain a distant figure, far removed from their daily life