The rule of the first emperor,
Augustus, (30 BC–AD 14) saw the foundation of the majority of the regiments attested in Hadrian's time. In the earlier part of this period, regiments were raised from and named after individual tribes, for example '
, ' and '
. Later, units were raised from and named after broad national groups, for example ', '
, and '. There is very little evidence concerning the organisation and policies of auxiliary recruitment. The ethnic origins of auxiliary recruits are attested in only a tiny fraction of cases. For example, the '''' must have recruited a calculated 8,000 soldiers over its probable lifespan of about 250 years but the origins of only two rankers are known. Conclusions about auxiliary recruitment drawn by scholars from the available evidence are regarded as tentative. According to Holder, during the
Julio-Claudian dynasty (AD 14–68), regimental ethnic identity was preserved to some extent, with evidence of continued recruitment from the original people. By the time of Hadrian, however, a regiment's name, in most cases, probably represented the ethnic origin of few, if any, of its members. This is because during the
Flavian dynasty (AD 69–96), as a matter of deliberate policy, most regiments were deployed in provinces far from their original home and drew the majority of their recruits from local natives and the rest from all parts of the empire. In most cases, therefore, a regiment's name had become an identification tag devoid of ethnic significance. A regiment deployed long-term in the same province would thus, over time, acquire the ethnic character of its host population. There are exceptions to this rule: • A minority of regiments remained stationed in their original home province, e.g., '''', still attested in
Dalmatia in AD 130. • Regiments founded a relatively short period before AD 130, for example '''' which was stationed in
Roman Britain in AD 130 would probably still have contained mostly
Dacian recruits at this time, as it had been established by Hadrian only about a decade earlier. • Some specialised regiments, such as Syrian archers and the elite
Batavi show some evidence of continued preferential recruitment from their original province. == List of '''' in the reign of Hadrian ==