INTRODUCTION
THE MILITARY REFORMS OF AUGUSTUS
An essay on the Roman auxilia might seem merely to be one of the many monographs in which students of the military system of the Roman Empire are patiently arranging material for some future scholar to utilize in a more comprehensive work. But while much space must necessarily be devoted to details of military organization, the subject opens up social and political questions of wider range. The extent to which a ruling race can safely use the military resources of its subjects and the effect on both parties of such a relation, the advantages and dangers of a defensive or an aggressive frontier policy, these are questions of universal historical interest, on which even an essay of so limited a scope as this must necessarily touch in passing.
As a preliminary consideration it must be realized that the use of troops drawn from the subject races was not an invention of the imperial government, but goes back to the most flourishing days of the Republic. The heavy-armed yet mobile infantry which formed the greater part of the burgess militia of the cives Romani and the socii constituted an arm which won for Rome the hegemony of Italy, and triumphed alike over the numbers and courage of Ligurian and Gaul or the disciplined professional armies of Carthage and the Hellenistic monarchies. In other branches of the serivce, however, the republican armies were less superior. Their cavalry, drawn, as was usualy in the armies of the ancient world, from the wealthier classes, was not sufficiently
