‘You will be wise to maintain a permanent force (στρατιώτας ἀθανάτους) raised from the citizens, the subjects, and the allies distributed throughout all the provinces in larger or smaller bodies, as necessity requires. These troops must always remain in arms and be drilled constantly; at the most suitable points they must prepare themselves winter quarters, and they must serve for a fixed period calculated to allow them a little freedom after their discharge before old age comes on. For we can no longer rely upon forces called out for the occasion, owing to the distance which separates us from the borders of our Empire and the enemies which we have upon every side. If we allow all our subjects who are of military age to possess arms and undergo a military training, there will be a continual series of riots and civil wars, while if, on the other hand, we check all military activity on their part, we shall run the risk of finding nothing but raw and untrained troops when we need a contingent for our assistance.’[14] The solution which Augustus found for this problem was then to revise the military system so that, while using as much as possible of the available material, he did not disturb the political conditions on which the equilibrium of the State depended. For it was no part of his intention materially to alter the structure of the Empire as an aggregate of states possessed of greater or less powers of self-government, held together by their subordination to Rome and withheld by their position from any independent external policy. Whatever possibilities he may have contemplated for the future he made himself few attempts to further the process of unification either by reducing the inhabitants of the privileged states to a lower grade or by the more generous policy of making wide extensions of the franchise and creating by this means a new imperial citizenship. This difference of status among the inhabitants of the Empire was naturally reflected in the military system. The _cives Romani_—that is to say, the inhabitants of Italy and of the few enfranchised communities among the provinces—furnished the new Household Troops, and the greater part, at any rate, of the recruits for the legions, and paid for their superior position as the ruling race by contributing much more heavily in proportion to their numbers than any other class in the population. The nominally independent monarchs of the client kingdoms were allowed and encouraged to maintain armies, often of considerable size, under their own control, and frequently led in person the contingents which they were called upon to bring to the aid of the regular troops when hostilities were taking place near their borders. These contingents were often numerous and capable of rendering valuable service. Thus Rhoemetalces of Thrace assisted in the suppression of the dangerous Pannonian revolt of 6-9, and Ptolemaeus of Mauretania was publicly