Monday, 28 December 2020

The Great Saint Bernard and the Roman route map

Border stone on the Great St Bernard Pass, early October 2020







 Monaco has been the scene of many notable victories but none quite so comprehensive as that commemorated in the village of La Turbie on the slopes overlooking the principality. The Tropaeum Alpium (or ‘Trophy of the Alps’) was built in 5 BC to honour the Emperor Augustus whose Roman armies, in a campaign lasting from 25 to 14 BC, cleared the Alps of all opposition, vanquishing 45 Alpine tribes in their wake. At the time of its construction, this now semi-ruined monument was 50 metres high and consisted of a tower surrounded by 24 columns and crowned by a statue of the victor. The triumphal arch lay at the western terminus of the Via Julia Augustus which originated in Placentia (modern Piacenza) and was later extended as far as Arelate (Arles), a route which before the conquest represented the only safe and secure way that the Romans could transfer their goods and troops to their northern provinces.

Half a century before the monument’s inauguration, Julius Caesar had conquered vast swathes of Gaul, a region encompassing roughly the equivalent of present-day France and Belgium. A major logistical obstacle for the Romans however, were the intervening Alps which remained in the hands of local tribes. For the Romans, gaining control of the mountain passes was a strategic necessity to supplying and thus expanding their Gallic possessions.

One of the key passes affording a more direct route north was the one we know today as the Great Saint Bernard. At 2473 metres above sea level, the pass is considerably higher than other major passes in the Western Alps, such as Montgènevre (1854m), Mont Cenis (2084m), the Simplon (2009m) and Saint Gotthard (2106m). The advantage of the Great Saint Bernard however, lay in its more accessible approaches and its directness from south to north through the Aosta and Rhone valleys.

To gain faster access to Gaul, in 57 BC Julius Caesar had attempted – and failed - to subdue the Alpine tribes along the Grand Saint Bernard corridor. It was left to Augustus, his adopted successor, to finally seize control of the entire Alpine region and conclusively ensure free access to the Roman sphere of control north of the mountain chain: heavy tolls exacted from passing troops and travellers by bellicose tribes could no longer be tolerated. The Salassi tribe who controlled access routes to the pass were eventually brought to their knees in 25 BC and the Aosta valley which they had occupied was depopulated, 44,000 people enslaved and a new Roman colony established at August Praetoria Salassorum (present-day Aosta): the Great Saint Bernard had been secured once and for all.

It was not until the reign of Emperor Claudius (41 – 54 AD) that a road was completed across the pass, on whose summit a mansio (an official lodging) and a temple, dedicated to Jupiter Poeninus, were constructed. (In pre-Roman times, the pass and the surrounding mountains went by the name of Poeninus or Poenini, supposedly the name of a mountain god who presided over the crossing). However ahead of their time Roman engineers were when it came to building roads, bridges, aqueducts and the like, roads at this height must have presented a completely different challenge, subject as they were to steeper gradients and mountain conditions, such as landslides and flooding, never mind the fact that the Great Saint Bernard would have been closed for 6 or 7 months of the year. The Romans were after all notorious for building direct routes, rather than those that followed the natural contours of the terrain and, of course, tracks capable of taking wheeled vehicles were limited in their gradient. It is unclear whether a track able to carry such vehicles went all the way to the top and it was likely that some goods would have had to be transferred to mule to negotiate the steeper slopes. However, sections of a Roman road on the relatively flat summit of the pass have survived.

If the maps the Romans left behind are to be believed – and there are precious few – the mountain passes, such as the Grand Saint Bernard and others further east, such as the Septimer and Reschen, were their key transport routes across the mountains. Nevertheless, for all their military might, expansionist drive, engineering prowess and attention to detail, the Romans left next to no cartographic legacy at all. If it hadn’t been for a redrawn copy of a map that surfaced in the Middle Ages, we might not possess anything at all. What is known however, is that the Romans compiled and kept route maps, called itineraries which linked routes between towns and cities and other prominent landmarks (such as villas, temples, spas, but also mountain passes) and, importantly, showed distance information. These itineraries were akin to modern-day urban transit maps, such as those we see above carriage doors on underground trains: the maps show only vital information, removing all unnecessary topographic detail. They are devoid of any scale or compass direction, so tell us almost nothing about the geography, retaining only the relationship between points along the route.

A detail from the Peutinger Table showing the Western Alps







The Tabula Peutingeriana, or Peutinger Table, was one such itinerary. This gigantic map, drawn on a parchment scroll 34 cm in height and almost 7 metres in length, depicts the extent of the Roman road network at the height of the Empire, containing detailed information about points along the way. To modern viewers, this map of Eurasia, stretching from the British Isles in the west to the Indian sub-continent in the east, is almost unrecognisable: the profiles with which we are familiar on the maps of today have been flattened, stretched and kneaded in such a way that they fit onto a format that was both manageable (for carrying around in rolled up form) and legible for troop movements. Key topographical elements, such as mountains (crenulated markings), rivers (wavy lines) and forests (lines of trees), feature sporadically to help us make sense of this distortion.

The Peutinger Table is a medieval facsimile which was most likely copied from a Carolingian version, which in turn is assumed to be a copy of a 3rd or 4th century Roman original. It is said to be loosely based on an earlier map first commissioned by the Roman general Agrippa in the 1st century and later engraved into marble near the Forum in Rome. The derived medieval copy came into the hands of an Augsburg-based scholar, Konrad Peutinger (1465 – 1547) – hence its name - who recognised that it was an important road map of the Roman Empire. It is now kept in the Austrian National Library in Vienna.

By no stretch of the imagination can the Peutinger Table be considered a mountain map, let alone a topographical map, given its warped perspective and scant reference to natural features. Instead, the map, which shows the vast extent of the Roman road network and settlements, is an implicit expression of the Romans’ world view, attempting - as the construction of the Tropaeum Alpium did several centuries previously - to demonstrate their power and control.

So can the map tell us anything about the mountains or, more specifically, the Alps? Well, yes. The mountain passes, clearly identifiable on the map, were the bridgeheads by which access to their colonies on the other side was facilitated. By establishing and holding onto these lines of communication through a system of fortifications, encampments and tollhouses, they were able to oil the wheels for the large-scale movement of troops and goods in either direction, thus by-passing longer and more complicated routes.

The map marks nothing more than a rudimentary starting point: it would be many more centuries before anyone would be able to make any sense of the mountains, at least in cartographic form.

Further reading:

Carreras C., De Soto P., Muñoz A. : Land transport in mountainous regions in the Roman Empire, Journal of Archaeological Science: Reports. Vol. 25, June 2019, pp 280-293

Snodgrass A.M.: The Early History of the Alps, The Alpine Journal 1993. Vol. 98, pp 213-222

Seidel, Wolfgang (2016): Sternstunden der Kartografie: Die abenteurliche Geschichte der Entdeckung und Vermessung der Welt, Malik / National Geographic

Noble-Wilford, John (2001) The Mapmakers, Vintage


This article was written as part of the Mapping the Mountains project