Alpine regiments of the Roman army
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 Rhaetian peoples and 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, when the regiments were still largely composed of Alpine recruits, it is likely that they were especially adept at mountain operations.
As would be expected from mountain people, the Alpine provinces predominantly supplied infantry; only one Alpine cavalry ala is recorded. About 26 Alpine regiments were raised in the Julio-Claudian period, the great majority under Augustus or his successor Tiberius. Of these, six regiments disappeared, either destroyed in action or disbanded, by AD 68. A further two regiments were raised by Vespasian. These and the 20 surviving Julio-Claudian units are recorded at least until the mid 2nd century, but by that time only around a quarter were still based in the Alpine provinces or in neighbouring Germania Superior. The rest were scattered all over the empire and would probably have long since lost their ethnic Alpine identity through local recruitment.
The Alpine peoples
Ethno-linguistic affiliation
There is some debate about the linguistic affiliation of the many known Alpine tribes. The names of most can plausibly be derived from Celtic stem-words implying a predominant Celtic element. Non-Celtic elements also existed, however. The Raeti are described as Etruscans by the classical authors, and probably spoke Raetian, a non Indo-European tongue apparently related to Etruscan. The Ligures, including the Taurini, were an Indo-European language but with an important pre-Indo-European substrate. Polybius, the earliest extant writer on Roman history, draws a clear distinction between "Celts" and Ligures. The Breuni and Genauni, two of the tribes on Pliny's list, are classified as Illyrian by Strabo.There is substantial evidence, however, that the non-Celtic elements had been largely assimilated by Celtic influences by the time of Augustus.
In the western Alps, the Ligures probably spoke an Indo-European language with strong Celtic similarities but also Italic, by that time. For example, Strabo describes one tribe in Provence as "Celtoligures". The Lepontii are one of the tribes classified as Raetian by Strabo. Their original language was therefore probably Raetian. But from the available inscriptions, the Lepontic language is believed to be Celtic, with some residual non Indo-European elements - a parallel to Celtiberian in Spain. The Raeti themselves appear to have undergone assimilation, as Livy states that their language had become much corrupted. Celtisation is also implied by the establishment of joint Raetorum et Vindelicorum regiments alongside the Celtic-speaking Vindelici, and by the union of the territories of both peoples to form the Raetia et Vindelicia province. This assimilation was probably the result of the great migrations of Gallic tribes across the Alps, which, according to Livy, started in c. 600 BC, continued until c. 400 BC and ended in the occupation and Celtisation of much of the Po Valley and of the Alpine regions through which the migrants passed.
The same process of Celtisation appears to have taken place in the eastern Alps. Before the immigration of the Celts, this region was dominated by Venetic and Illyrian tribes such as the Carni and Istri respectively. But little trace of the non-Celtic tribes has remained in the placenames, personal names and inscriptions of Noricum. The Veneti are convincingly attested only in the Gail River valley in the south of the region, while Illyrian evidence is very scarce. In contrast, over 800 secure Celtic attestations are known. The evidence suggests that, as in the western Alps, the non-Celtic elements were either displaced or assimilated, while their native languages had virtually disappeared by the time of the Roman conquest.
Overall, it is likely that Gaulish Celtic was the lingua franca of the Alps until replaced by Latin during the centuries of Roman rule: Livy states that Hannibal's guides for his crossing of the western Alps in 218 BC, who were Gallic Boii from the lower Po valley, could understand the "wild men of the mountains" through which they passed even when the latter spoke among themselves. In addition, the ancient authors often refer to the people of the eastern Alps as Galli transalpini.
Material culture
Although the Alpine tribes are described as "wild" or "savage" by the classical authors, their material culture was sophisticated, as it was predominantly of the La Tène variety, which is characterised by advanced metal-working techniques and of elaborate metal artwork. Indeed, the eponymous La Tène site is in the Alpine region, on Lake Neuchâtel, Switzerland. La Tène gradually replaced the pre-existing Halstatt culture in the eastern Alps in broadly the same period as that region was infiltrated by the Celts. Some scholars thus regard La Tène as a specifically Celtic culture, although most recent experts reject the linking of material culture to ethnic groups. In any event, by the time of the Roman conquest, the entire Alpine region was predominantly La Tène, including patterns of settlement and funerary rites.One especially important feature of Alpine culture was chalybs Noricus, celebrated in Roman times, from the region of Noricum. The strength of iron is determined by its carbon content. The wrought iron produced in the Greco-Roman world generally contained only minimal traces of carbon and was too soft for tools and weapons. It thus needed to be carburised to at least 1.5% carbon content. The main Roman method of achieving this was to repeatedly reheat the wrought iron to a temperature of over 800 C and hammer it in a charcoal fire, causing the iron to absorb carbon from the charcoal. This technique had been developed empirically, as there is no evidence that ancient iron producers understood the chemistry involved. The rudimentary methods of carburisation used rendered the quality of the iron ore critical to the production of good steel. The ore needed to be rich in manganese, but also to contain very little, or preferably zero phosphorus, whose presence would compromise the steel's hardness. The ore mined in Carinthia fulfills both criteria to an unusual degree. The Taurisci Celtic people of Noricum empirically discovered that their ore made superior steel around 500 BC and established a major steel-making industry around it. At Magdalensberg, a major production and trading centre was established, where a large number of specialised blacksmiths crafted a range of metal products, especially weapons. The finished products were mostly exported southwards, to Aquileia, a Roman colony founded in 180 BC.
Roman conquest
Introduction
When he assumed sole control of the Roman empire in 30 BC, the emperor Augustus was faced with a pressing strategic anomaly. Although Rome had subjugated all Gaul up to the Rhine and much of Illyricum, the Alpine region which separated these possessions from Italy and from each other remained outside Roman control and in the hands of independent mountain tribes. These were warlike and troublesome, alternately attacking and robbing transient Roman troops and supply convoys or exacting exorbitant tolls from them for the privilege of using the key Alpine mountain passes e.g. the Salassi, who reportedly ambushed Julius Caesar on one occasion by hurling rocks on his army, charged Messalla extortionate fees for supplies and forced the escaping murderer of Caesar Decimus Brutus to pay a toll of one denarius per man to allow his army to cross the Great St Bernard Pass in 43 BC. That Rome's overland communications with its transalpine territories should be thus held to ransom was no longer tolerable, especially as Augustus was intent on advancing the Roman sphere of control as far as the Danube river.A secondary strategic aim of annexing the Alpine regions was to seize control of their substantial mineral wealth, which included gold and the prized iron ore of Noricum.
File:La Turbie BW 1.JPG|thumb|right|The Tropaeum Alpium, a monument to the emperor Augustus's victory over the tribes of the western Alps. Erected 7 BC. In foreground, the village of La Turbie, near Monaco
File:Alta val di Susa.JPG|thumb|right|The Val di Susa, through which ran the main Roman road across the Alps from Italy to Gaul, via the Col de Montgenèvre, which lies in the left background
File:Arco di Augusto-Susa.jpg|thumb|right|Triumphal arch dedicated to Augustus at Susa, Piedmont, Italy. Erected by Cottius, king of the Taurini, in 8 BC, to celebrate his appointment as Roman governor over the local Ligurian tribes of the Alpes Cottiae
File:CohMont1.jpg|thumb|right|200px|Tombstone of Marius son of Ructicnus. The inscription states that he was a miles of the Alpine infantry regiment Cohors I Montanorum, who died in his 25th year of service. His heir, who erected the stone, is named Montanus, the same ethnic name as the regiment's, meaning a native of the eastern Alps, most likely the origin of the deceased. Note the Alpine edelweiss flowers, called stella Alpina in Latin. These were either a regimental symbol, or a national symbol of the Montani. The crescent moon-and-star motif between the flowers may be either a regimental emblem or a religious symbol. Date: 1st century, probably ante 68. From Carinthia, Austria
In the period 25-14 BC, therefore, Augustus' generals subdued the entire Alpine region. In Augustus' own words: Alpes a regione ea, quae proxima est Hadriatico mari, ad Tuscum pacari feci, nullae genti bello per iniuriam inlato. Although the latter claim is questionable, there is no doubt about the comprehensive and permanent nature of Augustus' subjugation of all the mountain tribes.
In 7 BC, Augustus erected the Tropaeum Alpium at La Turbie to commemorate his conquest of the Alps. The inscription on the monument, transcribed by Pliny the Elder, listed 45 Alpinae gentes devictae, including the Raeti and Vindelici. However, the names of tribes in the eastern Alps are not included, leading to the suggestion that the subjugation of the latter was achieved with much less bloodshed.