ABSTRACT
ON the frontiers the aim of the Flavian emperors was not so much to add fresh territories, although they did that also, as to render Roman soil inviolable. Augustus had not delimited the frontiers strictly; on occasions he had used his legions as a field force instead. Their task was to maintain internal order as well as to repel external attacks, and for this purpose their fixed camps were usually of earth and easily transferable. In general Augustus had sought natural boundaries such as rivers, mountains, oceans and deserts. Where these were lacking, his frontiers had not been firmly demarcated. Thus in the Germanies, in Raetia and in Syria the exact extent of Roman territory not bounded by rivers was left somewhat uncertain. Yet clearly defined and, if possible, short frontier lines were an urgent necessity in order to facilitate administration, and above all to enable the none too many legions to discharge their wide-flung duties efficiently. The Flavians sought to mark out such frontiers.
