The Alpine regiments of the Roman army were those auxiliary units of the army that were originally raised in the Alpine provinces of the Roman Empire: Tres Alpes, Raetia and Noricum. All these regions were inhabited by predominantly Celtic-speaking tribes. They were annexed, or at least occupied, by the emperor Augustus' forces during the period 25-14 BC. The term Alpine is used geographically in this context and does not necessarily imply that the regiments in question were specialised in mountain warfare. However, in the Julio-Claudian period (27 BC - AD 68), when the regiments were still largely composed of Alpine recruits, it is likely that they were especially adept at mountain operations.