The Late Roman Armies

8/7/2019 The Late Roman Armies

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The Late Roman Armies

The army of the Tetrarchy

The field armies

Under Diocletian the frontier armies bore the brunt of the defence of the empire. The role of the field armiesdecreased somewhat as political stability meant that usurpations were a lesser threat that they had beenbefore. Each of the tetrarchs had a small sacer comitatus at his disposal. The nucleus of these imperial fieldarmies was formed by guard units and a select number of permanently attached detachments from theprovincial armies. For large campaigns these formations were temporarily joined by vexillationes from thefrontier forces.

The tetrarchic field armies were made up of a number of different formations. Detachments from thepraetorian guards, both infantry and mounted troops like the equites promoti , were permanently attached tothe retinue of the emperors. These units were by this date also known as cohortes palatinae . The old equitessingulares Augusti still existed as the imperial horse guard, although these guardsmen had traded in their name for equites dominorum nostrorum . New guard units had been created in addition to the old. A mountedschola scutariorum was probably already part of the imperial guard. The unit of protectores consisted of

promising men being groomed for higher commands. Elite legionary detachments like the Ioviani andHerculiani drawn from the legio I Iovia Scythica and legio II Herculia and the lancearii recruited among thelegionary light infantry were permanently attached to the comitatus . Vexillationes of picked cavalrymen fromthe frontier units and elite auxilia were also included.

The frontier armies

The reign of Diocletian and his fellow emperors saw a massive increase in the number of legions. Therewere 39 legiones in existence in 286, but this number was almost doubled over the next thirty years. This didnot however mean that the total strength of the army was increased on the same scale. Although thestructure and establishment strength of these new formations were similar to that of earlier units, some of thetetrarchic legions were formed by combining existing units of the auxilia . These formations were distributed inpairs among the new, smaller provinces. Some new auxiliary units were also created, but the overall strength

of the auxilia probably dropped as a result of the formation of legions from auxiliary cohorts.

Recruitment for the enlarged armies proved to be a problem. Not only were old conscription regulationsapplied with more severity than before, but several new measures were introduced to fill the ranks. Sons of serving soldiers and veterans were now by law required to enlist in the army. The protostasia , a recruitmenttax on landownership, was a novel measure. Landowners were obliged to furnish army recruits in proportionto the size and yield of their properties. Those owning only small tracts of land were grouped together andtaxed collectively. Not all parts of the empire were subject to levies of men. In the provinces whosepopulation was considered to lack the required martial spirit, the recruiting tax was converted into paymentsof money known as the aurum tironicum or recruit gold. This money was used to provide bounties to attractvolunteers. Men were also recruited from outside the empire, either voluntarily or by the incorporation of barbarian POW's in the army.

The late Roman army

The field armies

The late Roman army contained several different field armies. Some of these, the socalled praesentalarmies, were under the direct control of the emperors and were the successors to the third century sacer comitatus . Other formations were based in the provinces and served as regional reaction forces. The fieldarmy units were composed of both palatini and comitatenses . There were few, if any, differences betweenthese classes of troops, though the former carried more prestige. Cavalry units consisted of vexillationespalatinae and vexillationes comitatenses that provided a mix of heavy, medium and light cavalry. Thelegiones palatinae , legiones comitatenses and the auxilia palatina consisted mostly of heavy infantry,although some units were also employed as light infantry and archers. The legiones pseudocomitatensesattached to some field armies were detached formations from the frontier armies. A new development wasthe formation of separate legiones of ballistarii . These formations consisted of artillerymen operating lighttorsion guns and crossbows.


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Unit organisations and establishment strengths for the late Roman army are difficult to reconstruct. Legionarydetachments had evolved into seperate units and were now termed legio rather than vexillatio . This meantthat a legio could compromise any number between 500 and 5000 men. However 1000 to 1200 soldiersappears to have been a common establishment strength for many of the smaller legions. The internalorganisation of these new legions is hard to establish. Although the ancient sources mention centuriae ,manipuli and cohortes , the references appear formalistic and may not reflect actual conditions. The auxiliapalatina consisted partly of newly raised units, but others had evolved from existing auxiliary cohortes . Their

strength and organisation were probably similar to those of milliary cohorts. Cavalry vexillationes are likely tohave been 500 strong with internal unit organisation similar to that of the earlier alae . A major break with thepast army organisation was the removal of mounted troops previously attached to infantry formations. Unitsin the late Roman army consisted of either horsemen or foot soldiers, not a mix of both.

Command of the field armies was normally in the hands of senior officers known as magistri , though minor armies could be commanded by a comes . There were some minor variations in the titles of the field armycommanders but there appears to have been little difference between the rank and function of a magister equitum , magister peditum or magister militum . Command of units of any kind was by now generally in thehands of a tribunus . These tribunes were professional military officers who had often served as a protector atthe imperial court. The tribuni vacantes were officers that were not directly attached to army formations andserved in similar capacities as the earlier centuriones supernumerarii . The designation praepositus merelyindicated the function of commander rather than an actual military rank. Centuriones were by this date more

commonly referred to as ordinarii and centenarii . Officers with identical titles served in both cavalry andinfantry units. Optiones recieved the new title of biarchus . Many other new designations for officers andNCO's appear in the sources, but are often difficult to interpret.

Unit titles in the later Roman army were of a slightly different style than those of their early imperialcounterparts. Although a lot of units retained names derived from unit numbers, like the Quarti Dalmatae , or their armament, as the Sagittarii Dominici did, there were a few peculiar late Roman practices. Manyformations carried the designations of seniores , the 'old ones' or 'veterans', and iuniores , the 'young ones' or 'recruits'. These titles were probably connected to a splitup of the armies among the sons of Constantine thatresulted in small cadre forces being detached from existing units to form the backbone of newly recruitedformations of the same name. As both types of unit received replacements in an identical fashion iunioresand seniores alike were soon composed of a similar mix of recruits and experienced men. Some late Romanarmy units also carried barbarian tribal names, but like the titles of earlier auxiliary units these were usually

not representive of the ethnic origin of its soldiers, the majority being of Roman rather than foreign extraction.

The frontier armies

The frontier forces were entitled limitanei or riparii . These consisted of infantry legiones , cohortes and numeri and cavalry vexillationes , alae and cunei . Frontier legiones were generally but not invariably larger formations than those found in the field armies with a strength and organisation resembling that of the earlier legions. Many units of the limitanei , both legionary and auxiliary, were divided over a number of small fortifiedbases. Often labelled a peasant militia with low fighting value in modern studies, these troops were in factprofessional military units not significantly worse in calibre from those in the field armies. The palatini andcomitatenses were regularly supplemented by forces drawn from the frontier armies.Armour and equipment

Contrary to popular opinion late Roman troops were as heavily protected by armour as their early imperialpredecessors. Although according to the available evidence the famous "lorica segmentata" was no longer inuse after the late third century, literary and depictional sources indicate a continued general use of scale,mail and lamellar body armour by both mounted troops and foot soldiers. A padded leather and linenprotective vest known as a thoracomachus was worn beneath metallic armour. Additional protection wasprovided by splinted greaves and armguards, notably in the ranks of the heavy cavalry. Helmet bowls wereby this date usually constructed of several segments. The distinction made in some modern works betweencavalry and infantry types does not appear to reflect ancient practice. Shields for all troop types weregenerally of oval or round shape. The unit shield patterns for many field army formations have beenpreserved in the Notitia Dignitatum , apparently with a remarkable degree of reliability.

Late Roman soldiers carried a variety of missile weapons. The introduction of new names for shaftedweapons tends to disguise the fact that there was little essential difference between early and later imperial

military practice. Heavy infantry continued to use javelins with long iron shanks similar to the earlier pilum .These could have both pyramidical points for better armour penetration or viciously barbed heads for useagainst unarmoured targets. Lighter javelins of different types remained the normal equipment of the cavalry,the light infantry and the rear ranks of infantry formations. There may however have been a greater


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emphasis on longer range fire power. A genuinely new addition to the armoury was the weighted throwingdart, the plumbata or martiobarbulus . This gave troops missile weapons with an improved range, thoughcarrying the penalty of a somewhat decreased penetration power. Also the more widespread indications for the incorporation of archers in javelin armed units may point to an increase in the proportion of archers in lateRoman formations.

The sword remained the weapon of choice for close quarter combat, though thrusting spears, daggers and

axes were also employed. From the second century AD onwards weapons with longer blades had graduallyreplaced shortswords in infantry service. The change in weapon type does not appear to have been linked toa drastic alteration in the tactics of the Roman heavy infantry. Troops continued to fight in close order formations using cut-and-thrust swordplay. Apart from the appearance of weapons and equipment little hadchanged from the days of the Roman republic.

Barbarisation

The late Roman army is often stated to have suffered from barbarisation, a deterioriation of old standards asthe result of the recruitment of large numbers of barbarians, especially Germanic tribesmen, from across theborders of the empire. In fact the recruitment of barbarians into the ranks of the late Roman army did nottake place in extraordinary numbers. Recent research indicated that even in the auxilia palatina , formerlyconsidered to be heavily barbarian in composition, only a fifth to a quarter of soldiers were of barbarian

extraction. Many early imperial army units contained a higher proportion of foreigners or only recentlysubjected barbarians. The majority of troops in the late Roman army were therefore of provincial Romanorigin.

Barbarian influence on tactics, equipment and organisation also appears to have been very limited. Thelonger swords used by Roman infantry soldiers from the second century AD were not a sign of changingtactics. The use of the Roman shortswords for stabbing rather than slashing has always beenoveremphasized in modern literature. Even the republican legionaries are explicitly described by Polybius toemploy their Spanish swords for slashing as well as thrusting. The longer blades of late Roman troops werepointed and would have increased their reach in close quarter battle. The spatha was in fact not a weaponthat Romans took over from Germanic barbarians, but a seperate Roman development of earlier Celticblades. As most weapons of this type found across the borders were imports from the Roman empire itappears that the barbarians adopted a Roman weapon rather than the other way round.

The performance in battle of late Roman troops was not significantly worse than that of their early imperialcounterparts. The Roman army had never been an invincible war machine. The battle at Adrianople fitted inthe list of Cannae, Carrhae, the Varian disaster, Tapae and countless other defeats. Even poorly armedJudean rebels destroyed the legio XII in the early stages of the Jewish War. The late Roman army had morethan a fair chance of victory against any barbarian opponent it met. Persians, Sarmatians and Germans allalike were defeated time and again.

Documents

The Late Roman Armies