The Roman Army, 31 BC–AD 337: A Sourcebook

4 The army in the field
THE DISPOSITION OF THE ARMY
There were twenty-five legions in service in AD 14, around 140,000
men, with probably an equal number of auxiliaries. Augustus
apportioned legions and other units to individual provinces where he
perceived a need, either because of inadequate pacification, or because
he intended a province to be a platform for aggrandizement. Indeed
Augustus greatly extended Roman territory in directions that suited
him, enhancing his own reputation, acquiring revenue, and bringing
prestige to the Roman state. In winter, the troops were scattered and
stationed in winter quarters, before being assembled in camps for
summer campaigns. These camps and winter quarters were not
permanent, though they might have stone-built accommodation,
especially in the cold northern provinces; in Syria the troops could be
billeted in towns. The Romans did not recognize any formal barriers
or limits to their power, and friendly kingdoms on the periphery of
Roman territory provided troops and an easy route to further expansion
when required. Britain was annexed in AD 43 and other peripheral
areas like Thrace were absorbed. Gradually, permanent bases emerged,
often accommodating two legions and a number of auxiliary units; but
during the first century AD these bases became smaller, containing only
one legion (see Figure 1; cf. also Plate 7), and consequently more
dispersed, while some auxilia units were stationed in separate forts;
the earliest auxiliary fort which is known in detail is Valkenburg in
southern Holland, built c. AD 40 (see Figure 2).
By the late first and early second centuries AD, it is legitimate to speak
of frontier zones, and in some areas in the second century a line was
clearly demarcated by the building of artificial barriers, as in Upper
Germany, Britain, Raetia, and Numidia. However, important areas, like
Dacia, lacked them. Furthermore, artificial barriers did not necessarily
have a common purpose, and while doubtless intended to contain any