There are few more fascinating valleys in Europe than the Val d’Aosta, the scene of the second stage in the game of strategy which Augustus was playing to bring peace to Northern Italy and to bind it to Transalpine lands, still recorded here in architectural works equaled by few in Italy north of Rome. Visiting this valley in midwinter for the first time, I expected to find it bleak and forbidding, leading up as it does to the very base of Mt. Blanc and Monte Rosa, but in the clear, still, and expanding atmosphere I could understand the apparent anomaly of the semi-tropical vegetation of the entire vine-clad valley, with its palms, its cacti, fichi d’India, rhododendrons, and so many of the same flowers that grow on the Riviera.
The Val d’Aosta stretches northwest for some sixty miles from the opening of the great Po valley at Ivrea, on either side of the river Dora Baltea. Even more than the Val di Susa above Turin does it give the impression of a long artery, often not two miles wide, leading into the very heart of the Alps. In the latter days of the Republic the valley was in the possession of the powerful and turbulent Salassi, a Celtic tribe that commanded both of the passes bifurcating from the little amphitheater where Aosta now stands: to the left the Little St. Bernard pass across the Graian Alps, and to the right the Great St. Bernard over the Pennine Alps. The Cromlech on the Little St. Bernard is the most spectacular record of the tribe, and proof of their racial and religious affinities.
The Romans of the Republic had no use for either of these passes, and merely founded, in 100 B.C., the city of Eporedia (modern Ivrea), at the base of the mountain valley, to coerce the Salassi and prevent their raids on the great plain, after they had been, since the war over the gold mines in 143 B.C., driven further and further up into the mountains. It also was the starting-point for a pre-Augustan control of the passes of the Graian Alps, used, for instance, by Julius Caesar.
That this remedy was hardly effectual, more than one punitive expedition attests. In any case it was not sufficient for Augustus, with his scheme to use the passes for his dreams of north-ern conquest and to communicate with the newly organized regions of Gaul above Provence. The special value of the Little St. Bernard was that it led, by the region of the Upper Isère and the Rhone, to Lyons, which Augustus made the administrative center for all Gaul and which he aimed to develop into the greatest Roman city in the west outside of Italy. By the same pass the region of the Rhine could be reached somewhat circuitously. It had been, always, the main route of the Celtic tribes into Italy. Soon also, in conjunction with the Brenner pass, further east, the Great St. Bernard was to be, not a source of danger to Italy, but a main artery of military communication in connection with the conquest of Rhaetia and Noricum; for it led to the region of the Rhone, Lake Constance, the Aar valley, and the Rhine ; and it was to serve the plans of the campaigns of Drusus in the north. Briefly, Aosta controlled the finest lines of communication between Italy, France and Germany.
In the Val di Susa and its Alpine passes the problem of Augustus had been simplified through the friendship for Rome of its confederated tribes under King Donnus, and his son Cottius. But in the Val d’Aosta, the more homogeneous and powerful Salassi were inveterate enemies; and so soon as Augustus had made the commercial route of Susa, further west, a part of the Roman network, he undertook, toward 25 B.C., their permanent subjugation. While he himself went to Spain and Gaul, he intrusted this minor but difficult affair to Terentius Varro Murena, who resorted to a sort of Cuban reconcentrado policy, which enabled him to substitute a loyal population.
It seems, in fact, a mistake to suppose, as even Mommsen has done, that Varro fought a pitched battle with the Salassi; rather, he left the lower end of the valley guarded, and worked his way up carefully to the summit until he reached the spot where Aosta now stands, where he established his camp. With the whole valley at his mercy and escape impossible, he organized a man-hunt. The Salassi, as was the custom with the Keltic tribes, lived in small open villages, in a loose cantonal union, and were practically defenseless. With a loss of less than two thousand killed of the Salassi, he corralled nearly 40,000 men, women, and children, took them to Eporedia and sold them all into slavery at public auction.
On the site of his camp Varro then founded a Roman colony, Augusta Praetoria Salassorum; a city modeled strictly on the plan of a permanent camp, and, like Turin, built as a fortress. It was named after the Emperor and the 3,000 veterans of the Praetorian guard who were assigned to it with their families. Some of the native Salassi came in to join the colony and were spared. The soldiers themselves built it. Placed at the upper end of the narrow valley where it widens out into a flat plateau before coming to an abrupt end, the city faces a pocket in the mountain range where it slopes down from the passes in a gently-curving hemicycle, and it is protected by two streams.
Only recently an inscription found near the west gate flatly disproves Strabo’s generally accepted statement that the Salassi were completely wiped out. It is a dedication to Augustus in 23 B.C. Of a statue (?) by “the Salassi who had joined the colony from its beginning.” Local archaeologists are mistaken in supposing the inscription to belong to the gate. Not only does its vertical shape disprove this, but the fact that this is a private dedication by a group of the inhabitants, whereas city gates cannot be dedicated except publicly by the whole city or the highest authorities. Therefore, before 23 B.C., the city of Aosta, with its walls, gates, and public monuments, must have been practically completed. Immediately below it the streams Dora and Buthier meet, in front of the famous “triumphal” arch forming the protection of the pomerium line of the city. It was a common Roman custom to take a natural boundary, whether for city, colonial territory or province. In this case the Buthier guarded the west and the Dora the south side.
A few of the initiated know that Aosta is one of the best preserved Roman fortified cities in the world. It is a rectangle of the length of 2,440 feet, the normal maximum length of a Roman camp-city, according to Hyginus ; its width is about 1,920 feet, which is wider than his norm (1,600 feet), but narrower than Turin. Its principal gateway, the Porta Praetoria, faces toward Rome; and in front of it, at a distance of 366 meters, stands the Colony Arch of the city.
This arch is on the sacred pomerium line that encircled the walls at that distance, marking the octroi line, the boundary between country and city jurisdiction. The line was originally marked by a trench dug by the consecrating priest with his sacred plow and oxen, as soon as the ceremonies by which the center and bounds of the new colony were determined had been concluded. No serious attempt has yet been made by scholars to determine the width of the sacred strip of land between walls and outer pomerium, within which it was forbidden to build. If I am right in placing the “triumphal” colony arches on this outer line, it will now be possible to determine this point in many cases, at Verona, for instance, at Gerasa in Syria, Thamugadi in North Africa, S. Remy in Gaul, and Telmessos in Asia-Minor to mention merely typical examples in different provinces of the Empire.
The Aosta arch stands directly in front of the superb Augustan bridge across the Buthier. Even though the original level of the arch is some two meters below the modern road, and though it is shorn of all its upper section above the triglyphal frieze, the structure as it stands is, next to that of Orange in southern France, the most impressive of all Roman memorial arches. This is due not merely to its immense bulk, but to the perfection of its simple outlines and pro-portions, nothwithstanding the fact that, unlike Orange, it is quite without decoration. It is not a structure with a core of brick or of roughly hewn blocks faced with marble, but is built throughout of carefully squared blocks of a sort of pudding-stone, quarried near the city above the banks of the Dora.
Besides the arch and the bridge, Aosta has the Porta Praetoria, the great stretch of encircling Augustan wall, with its towers, the ruins of the theater, of the amphitheater, the thermae or baths, the military granary, scanty remains of temples, and the many fragments of the Roman drains, streets, and houses. Near it is an unusual series of bridges, including the unique Pondel, with its double covered passage.
One of the most unusual things about all these constructions is that they were all,with the exception, perhaps, of the amphitheater,built at one time, when the city was founded: all in one style, with similar materials, according to a preconceived plan. We find something approaching this unity in the frontier cities of Syria and Africa, also built by the military engineers and workmen belonging to the legions, but these other instances are all of later date and supplemented by subsequent growth of population. Here at Aosta, in the quiet mountain silences, far from any causes for expansion, the city stayed as it was first built and before long the causes that led to its foundation were for-gotten, until the latter days of the Empire when once more, after four centuries, the northern hordes harried Italy from across the Alps,
What is quite recent is the discovery of the existence of two lateral gates. Until this discovery it had been supposed that, contrary to general usage, Aosta had but two gates, at each end of the main thoroughfare, the decumanus maximus. One of these is the gate now standing, not far from the arch; the other, the Porta Decumana (west), still existed until 1808, when it was demolished. It opened out toward the Little St. Bernard. In the other two sides (north and south) of the rectangle at each end of the cardo, the main artery that intersected the decumanus, the two customary gates had not been traced, and this defect was explained on the supposition that when Aosta was built there was only the pass of the Little St. Bernard to consider, so that no gate was required in the north wall. Even Mommsen was misled into this fallacy, which is quite obvious as soon as we understand that what Augustus had in mind in the subjugation of the Salassi was precisely, in great part, the opening up of the Great St. Bernard in connection with his proposed conquest of Rhaetia and Vindelicia.
The remains of the north and south gates have now been discovered, so that Aosta, like Turin, had four gates, but unlike Turin they varied in size, those on these minor faces having but a single archway, while the principal gates had three openings. This plan harmonized with the regular Augustan norm which gave a width of forty feet to the decumanus street and only twenty feet to the cardo street.
Of the new gates, only the Porta Principalis dextra on the south side is comparatively well preserved up to a certain height. I was not able to visit its foundations, which were found at a considerable depth below the present level, nor the little museum in the neighboring ancient tower, because the keys were, I was told, in Turin. Nobody wanted them in Aosta, it seemed, because the local inspector of antiquities had quarreled with the Direzione in Turin, and the Aostan worthies who had been offered the keys had all declined for fear of offending this inspector, whose influence was as strong as his temper was violent! Hence, I had to study the inscription supposed to belong to this gate in a cast at Turin, later on.
The walls, if restored with the battlements that originally crowned them, were considerably over IO m. high. They were formed of a core of rubble faced with an emplecton of small blocks of calcareous tufa, and defended by six square towers on each side.
The Porta Praetoria is in its way as impressive as the Colony Arch, and, besides, it is unique in the perfection with which it preserves the plan of the Augustan military gateways. Like the rest of the gates and the walls, it is built, not of bricks like Turin, but of large blocks of stone. These are not very carefully finished because they were originally faced not only with thin stone blocks but with a still thinner marble revetment in which the archivolt moldings, cornices and other architectural details were cut. The flanking towers are not polygonal, as at Turin, but square, and project boldly both within and beyond the walls. Both inner and outer façades of the gateway remain nearly intact, inclosing the large central court, where, if the enemy should penetrate, he could be attacked on all sides by the garrison. It does not produce its full effect, because the present street is two meters above the old level, and also because the gate has lost its upper story and its battlements, as well as most of the artistic facing with its architectural moldings. But it still is almost oppressive in its impression of force and bulk. A restoration taken from Promis’ Antichità di Aosta is in the main based on existing remains, except for the two reliefs which I consider improbable as well as decidedly out of place in the design.
The arrangement of the walls for defensive purposes is interesting. They are not very heavy, being only eight feet thick at the base and six feet at the summit. The diminution is obtained, not as in imperial times by a raking line but by rebates. This narrowness of the walls would give a width of only four feet at the top for the chemin de ronde to be used by the garrison in the defense, if we deduct the two feet of parapet and battlements. But this was over-come by running out at intervals of about forty feet heavy buttresses which not only served to strengthen the wall but to support a continuous internal wooden platform ten feet wide, which gave a total width of fourteen feet to the chemin de ronde. It was reached by stairways in the various towers. Of these towers the best-preserved is the one on the south side now called Tour de Pailleron.
The internal arrangement of the Augustan city is made quite certain by the lines of original under-drainage which have been discovered. These divided the city into sixteen large rectangular sections or insulae of almost equal size by four streets beside the two principal avenues: the decumanus street, east-west, and the cardo street, north-south.
The theater, not far from the Porta Praetoria and in the same region as the amphitheater, is of most remarkable form, for its extremities on both sides, instead of completing the regular curve, are cut abruptly by the rectangular lines of the streets on either side. The builders were evidently not allowed to spoil the symmetry of the town by breaking the continuity of one of the main arteries. Only the three inner rows of the hemicycle of sets are complete, while the two outer rows are cut. Promis compares this arrangement with that of the theaters of Industria, of Pompeii (smaller), and of Amemurium in Cilicia. The reason for this inartistic arrangement at Aosta is quite evident. In a purely military city such as this, where the ex-tent was determined entirely by strategic reasons, there had to be absolute economy of space. It is interesting to see how the architect tried to make the best of the adverse circumstances. There was also a structural reason, as I will explain.
Of the outer façade about a quarter remains on the south side, rising to a considerable height in primitive simplicity and strength. Its height is twenty-two meters. There are very few ruined Roman theaters in the west so imposing and few that are as early, for it is contemporary with the theaters of Balbus and Marcellus in Rome, and in point of style is earlier. In fact it is the only example of the purely Roman composition be-fore the introduction of the Hellenic false architrave and engaged shafts as the decorative framework for the arcades. Here the arcades appear in all their bareness, as they do in the purely structural bridges, viaducts and aqueducts. This theater at Aosta is really the finest example of the traditional style of the Roman engineer such as must have been used in the gates and basilicas of Rome in the Republican age before the time of the Tabularium or what-ever other civil structure first embodied this union of Greek and Roman forms. The elevation of the theater shows four stories, three arched and the lowest flat-topped. Its structure has a common combination of the late Republic: the opus quadratum of the heavy piers, archivolts and but-tresses is of heavy squared blocks of the same local pudding-stone as the colony arch; while the core and foundations are of irregular tufa scales, the opus incertum is of the broken river pebbles and the small and carefully tooled blocks that form the bulk of the facing are of calcareous tufa, not very different from the structure of the walls of Spello, of the age of the triumvirs.
The most striking feature is, however, the great buttresses of large slightly bossed blocks which divide each main bay of the theater façade from top to bottom and give picturesqueness and vigor to the outlines of the façade which would otherwise seem somewhat flat. They make one forget to miss the superposed Doric, Ionic and Corinthian orders of decoration, which decorate the usual imperial theater and amphitheater. It is not that the builders were ignorant, because they used the decorative orders in the amphi-theater and in the Porta Praetoria.
The reason for these buttresses and for certain other peculiarities, especially the triple row of windows and the inclosed portico behind the seem, is that we have here the rare form of the covered theater, the theatrum tectum. In a few cases, as at Pompeii, a small covered theater was built to supplement the usual larger uncovered theater. Here at Aosta, with its severe northern climate, the covered theater was adopted absolutely. So, while the façade of the Pompeian example measures but twenty-seven meters, this at Aosta is nearly double, with its forty-eight meters. I can cite another example of covered theater, that of Lillebonne in France, the Roman Liliobona. The plan is an almost exact counterpart of Aosta. After comparing the grandi-ose effectiveness of the Aosta façade with Brunelleschi’s splendid rusticated façade of the Pitti palace, Durm suggests that Aosta may have given to modern architects the scheme for some of the most impressive recent theaters, especially in Germany, at Munich, Vienna and Bayreuth! At all events we can well afford to give the Aosta theater a second look!
The Baths or thermae are of comparatively recent discovery and seem to have been restored in the time of Marcus Aurelius. Three semicircular exedrae and part of the main façade remain, and traces of a rectangular court surrounded by dressing-rooms.
Of the amphitheater the ruins are in such poor condition that it is interesting mainly for its great antiquity, antedating, as it probably does, the Coliseum, the amphitheaters of Capua, Verona, Pola and the rest. Its constructive methods, with their use of the Republican opus incertum, with the bossing of the stone-work which went out of fashion with Claudius, shows this early date quite plainly. Also its position inside the walls is unusual and due to the purely military character of the city. In most cases amphitheaters were placed at a short distance outside the walls or city limits, by the main highway.
Perhaps the most characteristic building of all is one that has left most of its traces under-ground. It was considered by Promis as the great military warehouse, and it bulks more largely on the plan than all the other buildings taken together. The store-rooms surround a large square in the center of which was a temple, perhaps the Augusteum,and the base of a large statue, probably that of Augustus. Two smaller temples occupied part of the side next to the forum (?) with its colonnade. The other three sides were formed by a perfectly regular series of store-rooms. Situated in a high and unproductive region, and liable when its construction was planned to be obliged to prepare for long sieges by invaders from the north, it was indispensable that Aosta should be provisioned for a long period and stored with arms, fodder and with everything required by both garrison and population. The technical arrangements of this great structure are interesting, especially in comparison with the much later warehouses at Ostia and elsewhere.
But I am inclined to agree with Durms’ suggestion that these underground vaults were more suited to storing water than grain, and that we have here the main cistern for the city, serving also as substructure to the colonnades surrounding the forum. It is impossible to deny the similarity of these parallel vaulted chambers with well-known cisterns such as those at Faicchio.
Aosta was made by Augustus the center of one of the three small military frontier districts, just beyond the borders of Italy, into which the Emperor partitioned the Alpine range. His idea was to keep the territory under his own personal control, as military districts, whereas Italy and other safe sections of the empire were under the civil rule of the Senate. This particular province was that of the Graian and Pennine Alps ; the first province was that of the Cottian Alps. Aosta was the end of Italy from the age of Augustus. Pliny says, in measuring the length of Italy, that it extended from the Alpine borders at Augusta Praetoria, which he describes as placed at the entrance to the two Alpine passes, those of the Graian and the Pennine Alps. It not only effectually blocked the way of invasion but was an aggressive point d’appui for an advance.
As Turin had corresponded to Susa, across the border, in Italy itself, so Eporedia, the modern Ivrea, corresponded’ to Aosta, some sixty miles distant. There are many interesting remains of the early road connecting the two cities. Eporedia was built on a hill where the river Dora swings out into the great plain, at the point where the main artery between Milan (:Mediolanum), Pavia (Ticinum) and the Rhine and Danube meet the east-west trading route. Though it was not an Augustan foundation, having been established in 100 B.C., its nearness to the Salassi had prevented any great development until the time of the foundation of Aosta, about 25 B.C.
Aside from remains of a theater attributed to the Antonines, its Roman antiquities have disappeared, though there is little doubt that excavations would uncover the earliest military bulwark of the extreme north.