ABSTRACT
The number of Roman citizens who bound themselves by military oath was about 500,000. At first glance, Octavian must have seemed an unlikely successor. Augustus in fact reshaped Rome's military apparatus, thereby strengthening the supremacy of the emperor as commander in chief and honing professionalization in the new army. In A. D. Augustus established a body of firemen, drawn from the humbler sectors of Rome's population. On the battlefield the auxiliaries performed different roles than the legionnaires and cavalrymen. The legion's command structure was fashioned like a pyramid that reflected the social structure of the Roman state. The soldiers were ranked in declining terms of social order, from top to bottom. One of the problems Augustus faced was how to prevent successful generals from using their armies independently of and against the central authority as many had done against the Senate during the civil wars.
