THE ROMANS AND their empire’s subject peoples had a range of institutional and noninstitutional approaches to handling conflicts and problems. We have treated the institutional end of this spectrum, especially policing. The scattered evidence reveals diverse police arrangements, and we can render this complicated variety more sensible by dividing it according to different levels: first, a fundamental dichotomy between civilian police (chapter 3) and soldierpolice. Our focus has been the latter, further divided into three sublevels: imperial (chapters 4 through 6), gubernatorial (chapter 7), and military (chapter 8). These different levels cooperated in the recovery of runaway slaves (chapter 2); we know that governors were sometimes involved with civilian police; and frumentarii worked across all military-policing levels. Civilian and military police occasionally worked together during the persecutions. Otherwise, there is not much evidence for joint operations, and these policing levels were not particularly well coordinated. Moreover, there were defects at every level, from cruelty and greed to basic ineffectiveness.
It is all the more surprising, then, that during the first three centuries AD, scores of powerful Romans (emperors, governors, procurators, mayors, councilmen) chose to expand policing. There were republican-era antecedents, but by and large, they followed the example of Augustus, who was willing to create new institutions to help keep order throughout the Roman world (chapter 4). He was most concerned with Italy and, above all, Rome, of course. The growth of military policing spread from there. To be sure, nothing within the time and space of our focus would match Rome’s eventual security complement of more than twenty thousand military police. Nearly all governors and procurators in the pax Romana would have been familiar with Rome, so they would have seen firsthand the advantages (and disadvantages) of having some kind of police force.
Perhaps the most important factor driving Roman military policing outside of Rome is the fact of an expensive, professional standing army. Everyone knew that the emperors’ power ultimately rested on the army, which enjoyed the investment of massive state resources. Soldiers practiced a range of skills that could be helpful in running an empire. Lacking anything like ancient