Chapter VII: Section III: The Use of the Auxilia for War and Frontier Defence

A history of the art of war under the Roman Empire has not yet been written, for the simple reason that we do not possess an account by a good military historian of a single campaign between that of Thapsus (46 B.C.) and that of Argentorate (357). Josephus does indeed give a first-hand account of the Jewish war of 66-70, and took some trouble over military details, but his subject limited him to siege operations and street-fighting. The most valuable section in his work is a general sketch of the Roman army and its organization, and a description of the arrangement of troops on the march.[311] Tacitus, on the other hand, who is forced by his subject to describe several campaigns, and remains in consequence our chief authority, cared nothing for the technical side of warfare, and does nothing more than record, as a rule correctly enough, details which he found in his sources.[312]

With strategy we need not concern ourselves, since the subject lies beyond the scope of this essay; but tactics require more consideration on account of the special position assigned to the auxilia in battle formation. From the scanty information given by our authorities it appears that in any regular engagement fought during the first two centuries the legionary infantry were still considered to be the chief arm and employed to deal the decisive blow.[313] They occupied the centre of the line, and the light troops and cavalry—that is to say, the auxilia—were expected to do little more than protect them from a flank attack. This formation was employed at Idistaviso in 16,[314] against Tacfarinas in 18,[315] against Tiridates in 58,[316] against Boudicca in 61,[317] and at the second battle of Bedriacum in 69.[318] It is also prescribed by Arrian in his ‘Order of Battle against the Alani’.[319] The only considerable exception is the battle of Issos in 193, in which the legions on both sides formed the first line and were supported by the archers, who shot over their heads. Dio, however, expressly states that this formation was adopted because these armies were fighting in a narrow space with the sea on one side and mountains on the other, so that there was no need to detach a force to protect their flanks.[320]

There were, however, cases, particularly in warfare against barbarians, where the enemy would not meet the imperial forces in the open field, but took up a defensive position on ground where legionaries could not be employed with success. In these circumstances the auxilia formed the first line and began the attack, and only if they were driven back and pursued by the enemy did the legions come into action. The battle of Mons Graupius, in 84, was conducted on these lines,[321] and similar tactics seem often to have been employed by Trajan in Dacia.[322] In general, however, the auxilia play a very secondary rôle; we do not hear either of the cavalry being used to strike the decisive blow after the manner of Alexander,[323] or of any such combination of archers and heavy infantry as we find in mediaeval warfare.

The subject, however, is still obscure, and it is more satisfactory to turn to the part played by the auxilia in frontier defence, concerning which the archaeological research of the past twenty years has established more certain conclusions. In the frontier policy of the first two centuries we can trace two opposing tendencies at work, each of which is reflected in the disposition of the troops and the duties required of them. At the death of Augustus the Empire had as yet reached hardly any of its natural boundaries, although by means of the system of client kingdoms and ‘protected’ tribes it was asserting its claims and intentions in much the same fashion as the powers of modern Europe are doing in Africa to-day. The first century therefore witnessed on almost every frontier a period of expansion of greater or less duration, in which the sphere of direct administration was gradually pushed forward until some physical or political obstacle was reached which necessitated either a halt or a forward policy on a much larger scale. Throughout this period military operations were always imminent; in Britain, for example, between 50 and 85, the garrison marched out almost every spring, either for a campaign or a military demonstration. In winter, therefore, or in times of peace, the frontier armies were so disposed as to be able to take the offensive at a few days’ notice. The legions often lay in pairs, while many of the auxiliary regiments, instead of being scattered over a wide area, as was the case later, were concentrated at a few strategic points. The extent to which this system was adopted varied, of course, with local conditions, and a few regiments always occupied more isolated positions, but as a whole the auxilia of a province were far more easily mobilized than later when each regiment had its own _castellum_. On the Rhine frontier Haltern and Hofheim furnish examples of these large _hiberna_, dating from the beginning and the middle of the first century respectively,[324] and we find the same system continued for the defence of the Taunus district annexed by Domitian.[325] There is, indeed, here a chain of forts on the frontier, but they are of small size, with an average area of only 1½ acres. The bulk of the auxilia lay some way behind the frontier, in forts which held some two or three regiments apiece.[326] In Britain we have traces of a similar system at the same date. The ‘Agricolan’ fort at Barr Hill is a frontier post which would require some two centuries at most for its defence, while the early fort at Newstead, which was probably occupied from about 80 to 100 or later, could accommodate at least 1500 men.[327] The essentially temporary nature of such _hiberna_ is emphasized by the character of their defences, which usually consist simply of an earth wall or palisade, little more elaborate in construction than the _vallum_ which an army in the field was expected to throw up round its camp after a day’s march.

In provinces whence archaeological evidence is not forthcoming, inscriptions indicate the same system. From Spain, for instance, we have an early inscription referring to an officer who held command over four cohorts,[328] and a similar brigade of three cohorts appears at Syene in Egypt in the reign of Trajan.[329] On the Danube frontier von Domaszewski has concluded from the epigraphical evidence that Aquincum and Arrabona each held two alae in the first century.[330]

This period of expansion may be considered to end with Trajan’s annexation of Dacia and his failure a few years later to execute a similar forward move on the Eastern frontier. With the accession of Hadrian a new policy begins, which advertised by the elaborate character of its defensive measures that the imperial government was firmly determined to renounce all further schemes of aggression, a determination which was adhered to until the power of decision lay no longer in Roman hands. The outward signs of this new spirit were the abandonment of the old _hiberna_, and the removal of their garrisons to stone forts of a new type, each arranged to hold no more than a single unit, which were placed at more or less regular intervals along the frontier instead of behind it.[331] The auxilia, that is, were transformed from a potential field army into a frontier police.

This policy of passive defence depended, of course, for its success upon the extent to which the frontier could be made defensible. Fortunately by this date it lay for the greater part of its length along positions of great natural strength. The Rhine, Danube, and Euphrates, when guarded by a continuous line of forts and watch-towers,[332] and patrolled by flotillas of guard-boats, formed a serious military obstacle to a raiding force, an obstacle even more dangerous to its retreat than its advance. The desert frontiers of Africa and Arabia were more easily defended, since the routes by which a hostile force could advance were limited in number and the defence could concentrate upon them, and the same of course holds true of the southern frontier of Egypt.

There were, however, districts where such natural obstacles did not exist, as in the case of the trans-Rhenane territory, which was divided between Germania Superior and Raetia, and the northern frontier of Britain, and here Hadrian had recourse to the expedient of erecting artificial barriers, which he hoped would serve the same purpose.[333] In the former case the frontier was defended by a palisade and ditch, which were later supplemented by an earth mound in the German section and replaced by a stone wall in Raetia.[334] On the British frontier, between the Tyne and Solway, the existing remains are those of a stone wall, although there are also traces of a wall of turf, which may have been an earlier work.[335] A turf wall also defended the more advanced line between the Firths of Clyde and Forth, which was occupied between 140 and 180.[336] The southern line in Britain in its most perfect form was guarded by a stone wall seventy-three miles long. This wall was between six and nine feet thick, and probably stood originally about twelve feet high. In front of it, except where the precipitous nature of the ground rendered such an additional defence unnecessary, ran a wide ∨-shaped ditch. At intervals of about every Roman mile stood a stone block-house, and between every block-house two towers. The mile-castles contained barrack accommodation for about fifty men, and reveal abundant traces of continuous occupation.[337] The garrison of about eleven thousand men lay in stone forts of the ‘cohort’ size, the majority of which are actually on the line of the wall, although a few, which probably belonged originally to an earlier system of defence, are a short distance behind it. The average interval between the forts is some six miles, so that it was easily possible for each regiment to man the adjacent towers and mile-castles and retain a considerable force at head-quarters. In addition to the troops actually stationed on the line of the wall, there were other regiments in outpost forts to the north and in the forts which guarded the three roads leading south to the legionary fortresses of Chester and York. The ends of the line were also guarded against flank attacks from the sea by forts at South Shields and on the Cumberland coast. If, then, we include all troops within three days’ march of the wall, the total force available for its defence probably exceeded twenty thousand men. Taking also into our calculations the natural strength of the position, we may safely say that this was the strongest and best guarded of all the frontier barriers.

The trans-Rhenane frontier, which extends for over three hundred miles from Rheinbrohl on the Rhine to Eining on the Danube, was defended by the same methods, although in certain sections the forts were more widely separated and the garrison was proportionately weaker. There were also fewer troops within call immediately behind the frontier line. Here also, between the cohort forts, stone ‘Zwischenkastelle’ and ‘Wachttürme’ furnished additional safeguards.[338]

This whole system of frontier defence has been much criticized, and the limitations and possibilities of these artificial barriers must be carefully determined.[339] To take the negative side first, they could not, of course, be defended against unexpected attack, like the walls of a town, unless the assailants were only a small raiding party numbering some twenty or thirty men. On the other hand, in spite of the parallel of the ‘Customs Hedge’ in India,[340] it seems unlikely that fiscal considerations played any large part in determining the government on their construction. They doubtless acted, when built, as a check on smuggling, but the expense of their maintenance would have been quite out of proportion to the value of the trade done with the German or British tribes.

The first purpose which they served was to furnish a screen behind which patrols could march in comparative safety, both by day and night, and keep the whole line under constant surveillance. Thus the passing of a hostile force could be instantly reported by messenger or signal[341] to the nearest _castella_, whence detachments could at once start in pursuit. Secondly, whereas the defenders nearly always had a mounted force close at hand drawn either from the _alae_ or the numerous _cohortes equitatae_, the raiders would probably be unmounted, since their start would be lost if they delayed to fill up the ditch and make a gap in the barrier large enough for their horses.[342] This barrier, too, had to be crossed again in retreat, and presented a very serious obstacle to a force encumbered with booty. Indeed, the defenders might reserve the great part of their forces for this moment, as is recommended by Byzantine military writers describing similar conditions.[343]

This sketch of the methods of defence employed applies more particularly to the German and Raetian frontiers. In Britain, more particularly on the southern line, it is probable that a more serious defence was intended. In the first place, the massive stone wall, on which the defenders could stand, was obviously stronger than anything on the trans-Rhenane section.[344] Secondly, we have noted that the garrison was stronger than in Germany, and could be more easily reinforced. Moreover, even after the final abandonment of Scotland, forts were still held in front of the southern line. Netherby on the Esk, and Habitancium (Risingham) and Bremenium (High Rochester) on Dere Street, were occupied by _cohortes miliariae equitatae_ well into the third century, and at the last two forts we find a _numerus exploratorum_ attached to the regular auxilia.[345] These strong outposts would have been able to check or harass the enemy’s advance and give warning to the garrison of the wall of any impending attack.

All these suppositions, however, both as regards Germany and Britain, are based upon the assumption that a raid would be the sole subject of the attacking force, and that it would not be too numerous to be dealt with by the garrisons of three or four _castella_. To a more serious invasion the resistance offered was much less effective. The legions, it is true, still remained in reserve, but they formed the only concentrated force at the disposal of the defending general, for the majority of the auxilia, scattered as they were along the entire length of the frontier, could not be quickly concentrated, and a provincial garrison can rarely have taken the field at anything like its full strength. The system also created serious difficulties when it became necessary to send troops from one province to the aid of another. Three regiments, for example, could not easily be sent from Germany to Pannonia, because each of them constituted an essential link in the chain of frontier defence. It became the practice, therefore, to form out of detachments drawn from several regiments a composite _vexillatio_ in which efficiency must have been greatly diminished by lack of _esprit de corps_. A cavalry _vexillatio_ of this type commanded by a certain Lollianus, probably during the Parthian war of Trajan, was drawn from no less than five _alae_ and fourteen _cohortes equitatae_.[346]

In defence of the system it would probably have been urged that on every frontier the hostile forces were equally dispersed and far less easily concentrated, and that a combination of the Celtic or Teutonic tribes would be heard of long before it was ready for action. The existence of the league which attacked and for a time broke through the Danube frontier in the reign of Marcus was certainly known to the imperial government, and the local governors succeeded in delaying the crisis until the return of the _vexillationes_ which had been sent to the eastern frontier, with whose aid they hoped to be able to cope with the situation.[347] Their calculations were upset by the havoc wrought in the army by the plague which these troops brought with them. Even so the danger was eventually surmounted, and the frontiers were on the whole successfully maintained for nearly a century more.

But the full consequences of this system cannot be perceived without some consideration of the changes which it brought about in the conditions of military life and their effect upon the general morale and condition of the troops. A very important point to notice is their immobility. Already in the first century there was, except for the officers, no regular system of transfers, and only an important change in the military situation caused troops to be sent from one province to another. In fact such changes were frequent, and considerable transfers took place, particularly during the Flavian period and the wars of Trajan. From the accession of Hadrian onwards, however, such movements cease almost entirely. During the following hundred and twenty years hardly a legion changed its position and the auxiliary regiments remained almost equally stationary.[348] We can trace regiments which remained literally for centuries in the same province and for the greater part of the time were in the same _castellum_. Of the twenty-one cohorts and alae which are mentioned by the _Notitia Dignitatum_ as forming part of the garrison of Britain, fifteen are shown by the evidence of diplomata to have been in the province long before the end of the reign of Hadrian; and two more, which occur in a diploma of 146, are probably only not mentioned earlier because they were creations of that emperor and had consequently no veterans ready for discharge until after his death.[349] Similarly the Cohors V Lucensium et Callaecorum was in Pannonia at least from 60 to 198, the Cohors I Hemesenorum from 138/46 to 240, and the Ala III Augusta Thracum from 148 to 268/71.[350] The best instance, however, is that of the Cohors II Ituraeorum Felix. This regiment is placed by the _Notitia_ in Egypt, and other evidence shows it to have been in the province in 147, 136, 98, 83, and probably 39.[351] As this section of the _Notitia_ seems to date, at the earliest, from the beginning of the fifth century the regiment was probably quartered in the same province for at least three hundred and twenty years.[352]

Evidence of continued stay in one _castellum_ is naturally more difficult to find, but the way in which the names Ulpius, Aelius, and Aurelius follow one another on a series of inscriptions of the Ala I Ulpia Contariorum from Arrabona in Pannonia Superior suggests that the regiment remained there throughout the second century, and the title Antoniniana shows that it had not moved before the reign of Severus Antoninus.[353] At the fort of Veczel in Dacia the Cohors II Flavia Commagenorum has left inscriptions dating from the reigns of Hadrian, Marcus, Septimius Severus, Severus Alexander, and Philip, which cover practically the whole period during which the province was in existence.[354] In Britain a remarkable series of dedications from Amboglanna (Birdoswald), which has already been referred to, shows that the Cohors I Aelia Dacorum was stationed there from about 211 to 271.[355]

Had the practice of employing a secondary title derived from the name of the reigning emperor commenced before the third century it would probably be easy to prove stays of much longer duration. The figures given above must certainly be taken as a minimum. A second-century auxiliary could thus make himself at home in his quarters in the practical certainty that, with the exception of a few temporary absences as member of a _vexillatio_, he would spend the whole of his twenty-five years of service patrolling the frontier on each side of his _castellum_.

In considering the life which the frontier guards would lead under these conditions we must remember that the character of the auxiliary soldier in the second century had changed considerably since the force was first organized by Augustus. In the early first century enrolment in the Roman service had little effect on the levies of wild tribesmen who composed the greater part of the auxilia at this period. They might be organized in Roman fashion, but the military qualities which they displayed and their whole manner of fighting were inherited from their ancestors. _Promptam ad pericula nec minus cantuum et armorum tumultu trucem_ is Tacitus’s description of a cohort of Sugambri employed in Thrace in the reign of Tiberius, and in like fashion the German cohorts of Caecina’s army shouted their war-songs and rattled their shields beneath the walls of Cremona.[356] In the second century all this was changed: the progress of Romanization had raised the majority of the provincials, even in the frontier districts, to a level of culture which placed them far above their ancestors of three generations back, although they might still seem barbarous to a cultured Greek or Italian.[357] In the conditions of the service there was nothing to prevent the auxilia from participating in this general advance, and the soldiers who spent the best years of their lives in these little frontier stations gathered around them all the amenities of provincial life which would have been found in any country town in the neighbourhood. On the sheltered side of the fort a civil settlement, technically known as the _canabae_, quickly sprang up, and soon contained as many inhabitants as the fort itself, if not more. It was here that the soldiers placed their wives and children, that retired veterans settled near their old comrades, and traders erected their shops. A bath-house or two and a few small shrines, particularly those dedicated to the popular military cults of Mithras, ‘the Unconquered Comrade,’ and Juppiter Dolichenus satisfied the highest material and spiritual needs.[358]

At the fort of the Saalburg, where such a settlement has been carefully explored, an area of something like seventy-five acres was covered with buildings and gardens. Shrines dedicated to the Mater Deum and to Silvanus and Diana have been found, as well as those of Mithras and Juppiter Dolichenus, and two others remain as yet unidentified. On the outskirts, here as elsewhere, lay the cemetery with its inscribed sepulchral monuments, the chief source of our information on so many points of military life.[359] On the British wall no _canabae_ have been so carefully explored as those on the German limes, which is the more to be regretted since the buildings are usually in a better state of preservation; but it is still possible to see near the fort at Borcovicium (Housesteads) the terraces on which a scanty crop was raised, while the remains of buildings extend down the hill from the fort at the top to a small Mithraeum in the valley.[360] At Cilurnum an elaborate bath-house was erected for the use of the soldiers of the Ala II Asturum on the banks of the Tyne, and further excavation would doubtless show that it did not stand alone. Where excavations have not taken place the existence of these and other buildings is testified to by inscriptions. At a fort on the Lower Rhine we even find the _praefectus_ repairing at his own cost the regimental clock.[361]

The married quarters mentioned above require a few words of explanation. Numerous critics of the Roman army have assumed not only that celibacy is a valuable military ideal, but that it was actually attained until Severus issued his famous edict permitting soldiers to marry while still on active service.[362] Previous to this it is assumed that they had no relations with women but those of the least binding description. Seeck, indeed, has carefully explained that the ‘children of the camp’ could not have been reckoned upon as a valuable source for recruits, because the rate of mortality is notoriously higher among illegitimate than legitimate children.[363] This theory is sufficiently refuted by the fact that, as we have seen, nearly fifty per cent. of the recruits for the Legio III Augusta in Africa were giving _castris_ as their birthplace long before the reign of Severus.[364] A recently discovered edict of Domitian has shown further that such unions were sufficiently permanent to be officially recognized by the government during a soldier’s period of service, although only legalized at his discharge.[365] The effect of Severus’s edict was merely to anticipate this act and give legal sanction to existing and perfectly well understood social conditions. Practically the change was probably of small importance, since it seems fairly clear that married quarters were not allowed inside the fort walls after this edict any more than before it, nor were married men allowed to remain permanently outside. Cagnat has shown that the arrangement of the internal buildings of the legionary fortress at Lambaesis, which are proved by epigraphical evidence to have been still existing in the third century, is entirely opposed to such a supposition, and to the general theory, which has often been advanced, that from the time of Severus onwards such a fortress became merely a club-house and exercise ground for the greater part of the troops.[366] These arguments are concerned only with the legionaries, but they are worth introducing because the erroneous views here discussed have often been made to apply to the army as a whole. In the case of the auxilia, indeed, there was never any justification for their acceptance. The evidence of the diplomata was always sufficient to show that even in the first century the auxiliary soldiers, like the legionaries, formed family ties during their period of service which were officially recognized on their discharge.[367] The same picture is given by early sepulchral inscriptions, of which the following, from the Pannonian fort of Teutoburgium, may serve as an example:

‘Ti(berio) Cl(audio) Britti f(ilio) Valerio, dec(urioni) alae II Aravacorum, domo Hispano, annor(um) L, stip(endiorum) XXX, et Cl(audiae) Ianuariae coniugi eius et Cl(audiae) Hispanillae filiae vivis ex testamento Flaccus dec(urio) frater et Hispanilla filia heredes faciundum curaverunt.’[368]

This tendency towards matrimony was naturally intensified by the more settled life of the second-century auxiliary. The systematic investigation of the cemetery attached to one of these permanent garrisons reveals as orderly a family life as could be found in any country town of the peaceful inland provinces. The following inscriptions, which are drawn from different parts of the Empire, are but few among many which might be advanced to support this contention.

xiii. 6270. From Borbetomagus in Germania Superior:
‘Faustinio Faustino Sennauci Florionis fil(io) mil(iti)
coh(ortis) I F(laviae) D(amascenorum), ped(iti) sing(ulari)
cos(consularis), Gemellinia Faustina mate(r) et Faustinia
Potentina sor(or) her(edes) secundum volumt(atem) testamenti
pos(uerunt). Vixit ann(is) [XX]V, decidit in flore iuvent(utis).
Faciendum curaverunt.’

iii. 10257. Teutoburgium in Pannonia Inferior:
‘M. Ulp(ius) Super dec(urio) alae Praetoriae c(ivium)
R(omanorum), ex s(ingulari) c(onsularis), ann(orum) XXXII,
stip(endiorum) XVI h(ic) s(itus) e(st). M. Ulp(ius) Similis
sesq(uiplicarius) alae I c(ivium) R(omanorum) frater, et Ulpia
Siscia soror, fratri pientissimo iuventutiq(ue) eius,’ &c.

iii. 10609. From Pannonia Inferior: exact provenance unknown:
‘D(is) [M(anibus)] Ael(io) Victorino ann(orum) XXX,
stip(endiorum) XIII, dupl(icario) al‹a›e I T(hracum)
v(eteranorum), et Ael(io) Liciniano an(norum) XII, filis
pient(issimis) Ael(ia) Flaviana infelic(issima) mat(er) et sibi
v(iva) p(osuit).’

_I. G. R. R._ i. 1350. From Talmis in Egypt:

τὸ προσκύνημα Γαίου Ἀ[ννέ]ου ἱπέως χώρτης αʹ Θηβ(αίων) ἱππικῆς
τύρμης Ὀππίου, καὶ Οὐαλερᾶτος ἰατροῦ υἱοῦ αὐτοῦ, καὶ Ἀρρίου
υἱοῦ αὐτοῦ, καὶ Κασσία[ς], καὶ Οὐαλ[ερί]ας, καὶ Ἐπαφρῦτος [καὶ]
…ρᾶτος τοῦ ἵππου [αὐτοῦ].[369]

These examples alone show how far from reality are Seeck’s licentious mercenaries and their neglected bastards. In fact the suggestion of many critics that celibacy is a valuable military ideal, which was attained, at any rate partially, until the relaxation of discipline by Septimius Severus, proceeds upon false lines. In a short service army, like those of modern European states, in which the whole time of the men is necessarily occupied in learning their military duties, such an ideal is practical enough. In the Roman Empire the adoption of a professional army with a service of twenty-five years put it beyond the power of any government to enforce such monastic conditions, and the facts of the situation were, as we have seen, never misunderstood by the imperial authorities.

This is, of course, far from saying that the resulting state of things was all that could be desired. The long service system is, on this account, open to serious objections in principle, and these objections are intensified when we consider the lines on which this system developed. The second-century auxiliary, encouraged by the settled conditions of his service to form matrimonial ties, with his wife and children comfortably settled just outside the fort walls, is perhaps a more satisfactory spectacle from the moral than the military point of view. Military service in the same regiment had not yet become actually hereditary, because the enfranchised son of the auxiliary was advanced a step in the social scale and enabled to take service in the legions. When, however, in 212 the Constitutio Antoniniana swept away a distinction which had long ceased to have any real basis in a difference of race or culture, this obstacle was removed.[370] Two sepulchral inscriptions of the Cohors I Hemesenorum, so often referred to, illustrate this change. The first is erected to a veteran of this cohort and to two sons and a grandson who had taken service in the neighbouring legions I and II Adiutrix, while in the second we find the son of a veteran from the latter legion who has taken service in the auxiliary cohort.[371]

It has already been noticed that the system of frontier defence organized by Hadrian made it difficult either to concentrate rapidly the garrison of a province at one point, or to send reinforcements from one province to another. The more settled the auxiliary regiments became, and the more local ties they formed, the more difficult did it become to order any dislocation of troops on a large scale.[372] In fact when Severus Alexander granted to the frontier garrisons any adjoining territory which had been captured from the enemy, insisting at the same time that their heirs could only inherit it on condition of military service, this act was the natural culmination of a long process of development which had transformed what had once been the finest field army in the world into a rural militia.[373] Unfortunately just as this development was completed and the result stamped with the seal of official approval, the emperors of the third century found themselves faced by new military dangers of a type with which the old system was least fitted to cope.

Footnotes:

[311] Josephus, _Bell. Iud._ iii. 5.

[312] He was not, however, an ‘unmilitary historian’ in the sense that, for instance, Ephoros was. Ephoros made elaborate accounts of military operations an important feature of his work, although he was quite lacking in military knowledge (Polybius, xii. 25); Tacitus never pretends to concern himself with more than the moral and social aspects of war. The same attitude may be observed both in Dio and Herodian (ii. 15, 6). This attitude was perfectly justifiable, since there existed, as we learn from this passage in Herodian and from Lucian (_De Hist. Conscrib._), a technical literature which would probably satisfy our needs. That we do not possess it is the fault, not of Tacitus and Dio, but of the Middle Ages.

[313] This was still the case at Argentorate in 357; cf. Ammianus, xvi. 12.

[314] Tac. _Ann._ ii. 16.

[315] Tac. _Ann._ ii. 52 ‘Legio medio, leves cohortes duaeque alae in cornibus locantur’.

[316] Tac. _Ann._ xiii. 38 ‘Socias cohortes et auxilia regum pro cornibus, medio sextam legionem constituit’. The defensive formation described in xiii. 40 is slightly different, since the legions in the centre formed a square.

[317] Tac. _Ann._ xiv. 34 ‘Igitur legionarius frequens ordinibus, levis circum armatura, conglobatus pro cornibus eques adstitit’.

[318] Tac. _Hist._ iii. 21 ‘Cohortes auxiliorum in cornibus, latera ac terga equite circumdata’.

[319] The legionaries were to occupy the centre, the auxiliary infantry high ground on the wings, the cavalry to wait in the rear.

[320] Dio, lxxiv. 7.

[321] Tac. _Agr._ 35 ‘Legiones pro vallo stetere, ingens victoriae decus citra Romanum sanguinem bellandi, et auxilium, si pellerentur’. It was not necessary for Tacitus to invent this not very creditable excuse. The tactics are those adopted with equal success against a Highland army by the Duke of Cumberland at the battle of Culloden in 1746. The same idea of checking the impetus of a Celtic charge by successive obstacles has often been suggested as the reason for the seven ditches which protect the exposed side of the fort at Whitley Castle, and the _lilia_ at Rough Castle on the Antonine Wall.

[322] They are particularly noticeable in the battle shown on Cichorius, _Die Traiansäule_, Pl. 45, and to judge from the column, the auxilia did more than their usual share of fighting in this war.

[323] In spite of the boasting of Antonius Primus, the achievements of the Pannonian cavalry in 69 were limited to a reckless advance followed by a disorderly retreat. Cf. Tac. _Hist._ iii. 2 with iii. 16. In the second century, however, we find heavy cavalry, _contarii_, who must have been intended for shock tactics.

[324] For Haltern see Schuchhardt, _Führer durch die Ausgrabungen von Haltern_. It is, however, perhaps incorrect to limit the garrison to auxiliaries: for Hofheim cf. Ritterling, _Das frührömische Lager bei Hofheim_, 1912. It was occupied from about 40 to 60.

[325] See Pelham, _Essays in Roman History_, p. 191.

[326] e.g. Friedberg has an area of (roughly) 10 acres, Okarben of 14, Heddernheim of 13, and Kesselstadt of 35. A cohort of 500 infantry was usually allowed about 5 acres.

[327] See Macdonald, _The Roman forts at Barr Hill_, pp. 11-15; Curle, _A Roman Frontier-post_, pp. 29, 349.

[328] xi. 6344 ‘P. Cornelio P. f. Sab(atina) Cicatriculae prim(o) pil(o) bis, praefect(o) equit(um), praef(ecto) clas(sis), praef(ecto) cohortium quattuor civium Romanor(um) in Hispania, trib(uno) mil(itum)’.

[329] iii. 14147².

[330] _W. D. Z._ xxi. 186, where this theory of the first-century frontier system is further developed.

[331] See Pelham, _op. cit._, p. 199. The forts on the North British frontier range in area from 2½ to 5½ acres, the largest (Amboglanna) being designed to hold a _cohors miliaria peditata_. The German forts seem to have been on a rather larger scale, and ran up to 15 acres, which is the area allowed at Aalen to an _ala miliaria_. It is not meant, of course, that forts of this type did not exist in the first century, but it was not until the reign of Hadrian that the dispersion of the auxilia in separate units was adopted as a general policy.

[332] Cf. iii. 3385 ‘(Commodus) ripam omnem burgis a solo extructis item praesidis per loca opportuna ad clandestinos latrunculorum transitus oppositis munivit’. This is from the Danube frontier.

[333] _Historia Augusta, Vita Hadriani_, 12 ‘In plurimis locis in quibus barbari non fluminibus sed limitibus dividuntur, stipitibus magnis in modum muralis saepis funditus iactis atque conexis barbaros separavit’.

[334] The best recent account of this frontier in English is Pelham’s essay, ‘The Roman Frontier in Germany,’ in the work already cited.

[335] Recent researches have, however, made it very doubtful whether a turf wall ever preceded the stone wall along the whole line.

[336] For this wall see the admirable account by Dr. George Macdonald, _The Roman Wall in Scotland_, Glasgow, 1911.

[337] The best description of the internal arrangements of a mile-castle is given by Mr. F. G. Simpson, in the _Transactions of the Cumberland and Westmoreland Archaeological Society_, vol. xi, New Series.

[338] The German Limes-Commission has not yet published its report on these works and the course of the frontier line in general. On the Walldürn-Welzheim section, which was built by Pius, the towers are at intervals of from 250 to 400 metres. Pelham, _op. cit._, p. 204.

[339] The view with which I find myself in most agreement is that of Delbrück, _Geschichte der Kriegskunst_, ii. 155-60.

[340] See Pelham, _op. cit._, p. 201 and appendix.

[341] The torches which project from the upper stories of the block-houses represented on the Trajan column have often been noted as indicating some method of fire-signalling.

[342] The palisade was not, of course, a board fence which could be torn down in a few minutes. It was made of oak-trees split in halves and bedded in a ditch four and a half feet deep. See Pelham, _op. cit._, p. 200. Some idea of its appearance can be gathered from the representation at the beginning of the reliefs on the Marcus column.

[343] Oman, _Art of War in the Middle Ages_, p. 209. He quotes Nicephorus Περὶ παραδρομῆς πολέμου.

[344] The stone wall on the Raetian frontier is of very inferior construction.

[345] The garrisons were: at Netherby, the Cohors I Aelia Hispanorum M. E., vii. 954, 963, 964, 965; at Bremenium, the Cohors I Fida Vardullorum M. E. and exploratores, vii. 1030, 1043; at Habitancium, the Cohors I Vangionum M. E., exploratores and Raeti Gaesati 1002, 1003. The latest inscription at Netherby dates from the reign of Severus Alexander; at Bremenium, the most advanced of the Dere Street forts, from the reign of Gordian III.

[346] iii. 600. See Appendix.

[347] Cf. _Historia Augusta, Vita Marci_, 12 ‘Dum Parthicum bellum geritur, natum est Marcomannicum, quod diu eorum, qui aderant, arte suspensum est’.

[348] The only changes which we know of are that Legio V Macedonica was transferred from Moesia Inferior to Dacia in the reign of Marcus and that Legio III Augusta was sent by Gordian III as a punishment from Africa to the Rhine, whence, however, it returned in 253. Cagnat, _L’Armée romaine d’Afrique_, pp. 156-61.

[349] The date of this section of the _Notitia_ is disputed, but it can hardly be earlier than the end of the third century. The diplomata are xxix (98), xxxii (103), xxxiv (105), xliii (124), lv (_ante_ 138), lvii (146).

[350] Cf. D. ii and iii. 3664, D. lviii and iii. 3331, and D. lx and iii. 11333. These regiments may of course have been temporarily absent, but the evidence is fairly continuous in each case. The Cohors V Lucensium et Callaecorum, for example, appears on diplomata for 60, 84, 85, 133, 138/48, 148, 149 and 154.

[351] _I. G. R. R._ i. 1348, ib. 1363, iii. 14147², D. xv, iii. 14147¹. In the last, which dates from 39, the number of the cohort is not given, and possibly another in the same series is meant.

[352] For the date of the Egyptian section of the _Notitia_ see my article, _The Garrison of Egypt_, in the account of the excavations at Karanóg by the Eckley B. Cox Junior Expedition to Nubia published by the University Museum, Philadelphia.

[353] iii. 4379 (3 Ulpii, 2 Aelii), 4360 (Aelius), 4369, 4370 (Aurelii), 11081.

[354] iii. 1371, 1372, 1374, 1379; _A. E._ 1903. 66.

[355] vii. 818 (Severus Antoninus), 819 (Gordian III), 820 (Postumus), 823 (Tetricus). Another inscription (808) dates from the reign of Maximin.

[356] Tac. _Ann._ iv. 47; id. _Hist._ ii. 22.

[357] Cf. Dio’s remarks on the impression made by the provincial legionaries in Rome in the reign of Septimius Severus, lxxiv. 2. The following sketch applies only to the troops on the Western frontiers, concerning whose life we have considerable evidence. The locally raised troops in the East started as a rule at a higher level of culture, but possibly a similar advance was made by Trajan’s regiments of Paphlagonians, Galatians, and Arabians, although here Hellenization, not Romanization, was of course the goal.

[358] For the importance of Mithras in the army, cf. Cumont, _Les Mystères de Mithra_. Toutain, _Les Cultes païens dans l’Empire romain_, cc. ii and iv, gives a classified list of the inscriptions of Mithra and Dolichenus.

[359] H. Jacobi, _Führer durch das Römerkastell Saalburg_, 1908, gives a summary of the latest results.

[360] Excavations so far have been confined to the fort itself, in which the buildings were in an exceedingly good state of preservation, and the Mithraeum.

[361] xiii. 7800 ‘Petronius Athenodorus prae(fectus) coh(ortis) I Fl(aviae) horologium ab horis intermissum et vetustate colabsum suis inpendis restituit’. The date is 218.

[362] Herodian iii. 8, 5.

[363] _Rheinisches Museum_, xlviii. 616 ff.

[364] viii. 18067.

[365] _A. E._ 1910. 75.

[366] Cagnat, _L’Armée romaine d’Afrique_, pp. 380-3 and 505-7.

[367] e.g. D. iii (64), a wife, son, and daughter; D. xcviii (105), a wife, son, and two daughters; D. xxxvii (110), three sons. See above, p. 32.

[368] iii. 3271. The approximate date of the inscription is sufficiently indicated by the names employed.

[369] This very comprehensive dedication comes from the shrine of Mandoulis, the source of many military inscriptions.

[370] The possibility that cives had already been admitted into the auxiliary regiments before this date has already been discussed. See above, p. 33.

[371] iii. 10316 and _A. E._ 1910. 144.

[372] The campaigns between Severus and his rivals (193-7) were fought out by vexillations; hence at the end of the war we find all the regiments on both sides, so far as they can be traced, in their old quarters.

[373] _Historia Augusta, Vita Alex. Sev._ 58 ‘Sola, quae de hostibus capta sunt, limitaneis ducibus et militibus donavit, ita ut eorum essent, si heredes eorum militarent, nec umquam ad privatos pertinerent, dicens attentius eos militaturos, si etiam sua rura defenderent’. The theory of the self-sufficiency of each provincial garrison could not be more clearly expressed.