IV

FLAVIAN WARS AND FRONTIERS

VI.  

THE WAR AGAINST THE CHATTI

It did not require the fate of Nero to remind Domitian that his own security and the peace of the world demanded at the very least that an emperor should know and be known by his troops. In the course of AD 83, within two years of his accession, he came to Gaul under pretext of holding a census and suddenly appeared on the Rhine. The Chatti were already in arms: it was his design to forestall attack and to crush that powerful tribe.

On the west and south towards the Rhine and the Main their territory in Hessen-Nassau stretched as far as did the Hercynian forest—the name given at one time or another in antiquity to all or to almost any part of the forests of Central Europe. To the north their neighbors were the Cherusci, now fallen from their pride and reduced to dependence on Rome, to the south-east the Hermunduri of Franconia and Thuringia who, since their establishment in those regions by Domitius Ahenobarbus, had enjoyed and had repaid the favor which Rome extended to them. Here were allies against the Chatti: but it is not known whether Domitian commanded the active co-operation as well as the good will of the Cherusci or the Hermunduri when he proceeded against their enemies. Nothing is recorded save that, perhaps some years later, Domitian supported, though only with money, a king of the Cherusci whose expulsion the Chatti had secured and whose return they sought to frustrate.

The triumph which Domitian celebrated over the Chatti was treated with derision. A tale once told of Gaius, a tale of slaves with dyed hair masquerading as German captives, was seasonably revived, and the battle of the Mons Graupius soon came to sharpen the contrast between real and spurious victories. It was not likely that Domitian's war would be signalized by any of those grandiose and sometimes futile battles, dear to a historian with a taste for the dramatic. The formidable Chatti, imitators of Roman discipline, and equipped, when they marched to war, with tools and supplies, were far too intelligent to be lured into a pitched battle.

The character of the Chatti and the nature of their land dictated the strategy that Domitian employed against them. Over a front of a hundred and twenty miles he drove military roads deep into the broken and wooded country that hitherto had secured them immunity and thus opened access to their fortresses. These were massive structures with ramparts of stone and timber, after the Gallic fashion, crowning the hilltops. A cluster of native hill-forts occupying spurs of the Taunus is to be seen not far south of the line which the Roman frontier subsequently followed; but whether any of them were occupied by the Chatti at this time is not known. Farther to the north, their land was dotted thickly with fortresses, such as the imposing Dünsberg near Giessen, or the Altenburg m the direction of Cassel.

The campaign of Domitian must have embraced much more than the territory that was to be an­nexed if that annexation were to be effective, permanent and secure. Operations conceived on so large a scale and carried out with such thoroughness demanded the employment of many columns of troops. About the auxilia, details of a great concentration are lacking: but there is some evidence for the legions. It was about this time that Domitian raised a new legion, I Minervia: this he dispatched to the camp of Bonna in Lower Germany, withdrawing thence XXI Rapax for service against the Chatti. So for a time there were five legions in the army of Upper Germany. But not for long—the creation of I Minervia would liberate a German legion for service elsewhere, and I Adiutrix soon departed from the Rhine: XXI Rapax took its place beside XIV Gemina in the camp of Moguntiacum. From Britain Domitian withdrew vexillationes of the four legions of that province. These troops fought in the war under the command of their own tribunes of senatorial rank. They appear to have been retained for a time on the Continent. Velius Rufus emerges into history again, between 83 and 85, as the commander of a force composed of vexillationes of nine legions—the four from Britain and the five of Upper Germany. Tiles of most of these detachments have been discovered at Mirebeau-sur-Beze (near Dijon) in the territory of the Lingones: and Domitian may have had his reasons for temporarily establishing a field-army under a soldier of tried worth and fidelity at this important strategic position. Yet even so, Velius Rufus may have employed his army elsewhere—operations designed to reinforce the security of the frontier of Lower Germany may well have been carried out in 83 or 84 as a complement to the crushing of the Chatti.

In the meantime Domitian had returned to Rome, conscious that he had earned the title of Germanicus which he assumed and the triumph which he celebrated shortly before the end of the year 83. Moreover by his presence with the armies and in the field he had attached the soldiers to his person. Their spontaneous loyalty he rewarded and confirmed by raising their pay.

Vigorous measures were taken for controlling the Chatti in the future. Along the crest of the High Taunus, north-westwards to the mouth of the Lahn and eastwards in a great sweep enclosing the region of the Wetterau as far as the Main in the vicinity of Hanau a chain of patrols was established. Wooden watchtowers were erected from four to seven hundred yards apart, and here and there, on or near the sites of the stone forts of Hadrian's day, tiny earth encampments of about seventy yards square. A salient is weak only if it is weakly held. In the plain below, between the Taunus and the Main, forts (at first of earth and timber) for cohorts and alae were established, at Wiesbaden, Hofheim, Heddernheim, Okarben and Friedberg, probably also at Hochst and at Frankfort. The eastern flank of this defensive system was secured by a stone fort at Kesselstadt (near Hanau) of unusual size, nearly four hundred yards square: it was designed either to hold a legion (there was temporarily an additional legion in the army of Upper Germany) or a small army of auxiliary regiments. A network of roads linked these forts with each other and with positions on the outer line of patrols. If the Chatti came again, their approach would be at once detected and their advance checked by a rapid concentration of auxiliary troops, supported, in the last resort, by the two legions from Mainz. It is not impossible that to these defenses was added the lesser security of a treaty.

In this way Domitian designed and created a new frontier beyond the Rhine between the Lahn and the Main. Of the territory so unequivocally claimed and so firmly grasped by Rome, little or none appears to have belonged originally to the Chatti. Even when they lay beyond the frontier of the Empire the friendly Mattiaci had been subject to Roman influence and control: their territory was now definitely annexed. The Usipi, however, to the north-west of the Mattiaci, were probably still outside the Empire. The Mattiaci were not the only native inhabitants of the land enclosed by Domitian's frontier. The region of the Wetterau had never been covered by forest: from neolithic times onwards its rich loess soil had supported a dense agricultural population, ever at the mercy of a stronger power. It might be conjectured that the Roman annexation was not unwelcome, bringing as it did protection from the raids and the exactions of the warlike Chatti. A tribe, the name of which cannot be identified, received compensation in money from Domitian when he erected forts in their territory.

Fertile land was thus acquired. Though economic considerations may have determined, here and elsewhere, the extent of the Roman annexations, they do not alone explain the purpose of those annexations. The region lying between Mainz and Hanau is of unique strategic importance, for so many routes of communication meet and cross in it. Northwards the Hessian Gap between Taunus and Vogelsberg provides the easiest approach to the Weser and to the Elbe—and conversely the easiest way by which a German invasion might reach the Rhine. The occupation of the Wetterau by a force based on Mainz practically cuts off North from South Germany. The significance and purpose of Domitian's measures is at once apparent. He pushed away from the Rhine the only formidable tribe in the neighborhood of the frontier, and by creating beyond the Rhine an enlarged fortified zone to repel or control the Chatti, provided for the security of the whole frontier to the south. It is no accident that the crushing of the Chatti was soon followed by an advance in the south which won for Rome the valley of the Neckar and a still shorter line of communications between the armies of the Rhine and the Danube, roughly the line Mainz-Heidelberg-Stuttgart-Ulm.

In the early years of Vespasian the campaign of Cn. Pinarius Cornelius Clemens had brought the Romans to Rottweil, not far from the sources of the Neckar. The advance made by Domitian did not proceed north-eastwards from Rottweil down the Neckar, but was a converging movement, from the plain of the Rhine eastwards to the middle course of the Neckar and from the Danube northwards and north-eastwards. For a time the two lines of forts, the German and the Raetian, seem to have overlapped in the south­west, even when in the last years of Domitian the easternmost forts of the Raetian line had been pushed forward almost to the ultimate line of the frontier. So much may be said of the advance in general. The details are mostly obscure.

In the first place, Raetia. The absence of a legionary garrison had an unhappy effect, not only upon the civilization of that province, but also upon the amount and quality of the historical and archaeological evidence. Nor is the material provided by the auxiliary forts of Raetia adequate to permit very close datings. The Danubian frontier of Raetia had long been neglected by the Roman government. Claudius posted forts along the southern bank of the Danube. Vespasian continued the work. Activity can be traced in the years 78-81. Now forts were constructed at Günzburg, a little east of Ulm, and at Eining, some twenty miles south-west of Regensburg. This might have been thought to preclude any intention of an advance north of the Danube. Yet in AD 80 a fort appears beyond the Danube at Kösching, about fifteen miles to the west of Eining. This fort can hardly have stood alone—it is probably a link in a chain of forts extending westwards a few miles beyond the northern bank of the Danube to Faimingen. This advance in the eastern sector of the Raetian forts might indeed be explained by local conditions—the southern bank of the river, marshy for a long stretch, does not provide a good line of lateral communication. In any event, it was not long before a more decisive step was taken in the western sector of the frontier of Raetia between Faimingen and the most easterly of the forts erected after the campaign of 72—4. Between the Danube and the upper reaches of the Neckar where that river runs parallel with the Danube extends a bare treeless plateau, rising gently from the Danube but descending abruptly to the Neckar—the Rauhe Alb, or Swabian Jura. Along the Alb, at points commanding the routes across it, runs a chain of forts, Lautlingen, Burladingen, Gomadingen, Donnstetten, Urspring.  Such is the Alb-Limes. How it was prolonged eastward from Urspring is uncertain. Perhaps at first by way of Heidenheim to Faimingen and the hypothetical line of east-Raetian forts beyond the Danube as far east as Kösching: perhaps rather by a more northerly line, which extended almost as far to the north as the Raetian frontier in its ultimate form. This latter advance, embracing the forts Oberdorf, Munningen, Gnotzheim and Weissenburg, had been carried out before the end of Domitian's reign; and it might even be contemporary with the Alb-Limes, which has been dated c. AD 85. The remains from the forts of the Alb-Limes are deplorably scanty. There are no inscriptions: the pottery from one of them, Burladingen, has suggested a date for its origin approximately five years earlier than Cannstatt on the Neckar.

As for the forts along the Neckar from Wimpfen southwards to Cannstatt and Köngen, the establishment of which was the complement of the moving forward of the Raetian forts, here too the evidence is by no means abundant. From the pottery, Cannstatt has been dated c. AD 90. Yet, the evidence being what it is, a slightly earlier date in each case might not be excluded, 85 for Cannstatt and 80 for Burladingen. Indeed, as both series of forts, the Alb-Limes and the positions on the Neckar, seem to be parts of the same process, a converging movement from the Rhine and from the Danube, they might be closely connected in time as well as in design. This advance in the south was not merely a sequel but a consequence of Domitian's victorious war against the Chatti and might therefore be presumed to have followed after no long interval. But the date affects only the speed at which the process was carried out, not the purpose, the methods or the result.

The Roman occupation of these territories proceeded quietly and peacefully: it had been carried a stage forward by the end of the reign of Domitian when the building of a chain of forts north­wards from Wimpfen across the Odenwald to the Main established a junction with the southern end of Domitian's frontier.  In the meantime, however, on another frontier the Empire had been subjected to the vicissitudes of a long and arduous contest.