Religion in ancient Rome concerned itself with (amongst other things) issues of control, prediction, and explanation, largely through the use of ritual, which was mostly designed to consult the gods or (if they proved adverse) to win their favor. Historiography, on the other hand, dealt with (amongst other things) issues of influence, warning, and explanation, largely through the representation of appropriate and inappropriate behavior. Clearly there is some potential for overlap: who had the last word in explaining how and why something had happened - especially when Rome had suffered a defeat and the stakes were high? It is not impossible to envisage a Rome where there was tremendous rivalry over whose account should predominate, and this hypothetical tension reaches its height when we consider that Tacitus was not just a historian but also a priest concerned with the interpretation of the Sibylline Books - which meant that he was one of those responsible for reviewing the past century or so of Roman affairs to discern the workings of Fate.