Military History of Late Rome 361–395

By Ilkka Syvänne

A comprehensive look at campaigns, battles, and military developments in these dramatic decades.

Part of a multivolume history spanning from AD 284-641 that offers detailed accounts of campaigns, battles, and the changes in organization, equipment, strategy, and tactics among both the Roman forces and her enemies in the relevant period, this book covers the tumultuous period from the death of Constantius II in AD 361 to the death of Theodosius.

Among the many campaigns covered are the Emperor Julian’s fatal campaign against the Sassanian Persians and the disastrous defeat and death of Valens at Adrianople in 378. Such calamities illustrate the level of external threat Rome’s armies faced on many fronts in this difficult period.

Praise for Military History of Late Rome 425–457

“An outstanding work . . . [the series] gives us a very good picture of the long process that has come to be known as the ‘Fall of Rome.’ This is an invaluable read for anyone with an interest in Late Antiquity.” — The NYMAS Review

• Language: English
• Publisher: Open Road Integrated Media
• Release date: Mar 30, 2014
• ISBN: 9781473872226

Ilkka Syvänne

Dr. Ilkka Syvänne gained his doctorate in history in 2004 from the University of Tampere in his native Finland. Since then he has written extensively about ancient and medieval warfare and his publications include: 'The Age of Hippotoxotai, Art of War in Roman Military Revival and Disaster 491-636' (Tampere UP 2004), 'The Reign of Gallienus' (Pen & Sword, 2019), the multivolume 'Military History of Late Rome' published by Pen & Sword and the critically acclaimed Caracalla. He is the co-author with Professor Katarzyna Maksymiuk of the 'Military History of Third Century Iran' (Siedlce UP, 2018) and the 'Military History of Fifth Century Iran' (Siedlce UP, 2019). He was Vice Chairman of the Finnish Society for Byzantine Studies from 2007 until 2016. He has been an Affiliated Professor of the University of Haifa since 2016. He lives in Kangasala, Finland.

Book preview

Chapter One

Roman Empire in AD 361

Overview

The Roman Empire Julian inherited in 361 was a dictatorship that had been formed in the cauldron of the wars of the third century that had brought about a great many changes to the administrative and military structures which had been followed up by additional reforms by Diocletian and Constantine. The following discussion gives only a summary of the principal features. For additional details see the first book in the series and the endnotes therein.

Diocletian quadrupled the size of the army and navy and stabilised the borders. He also created local reserve forces that operated under the duces just behind the borders, and continued the practice of having sizable military force (Comitatus) around the emperor. Diocletian also successfully reformed the administrative structures by dividing up the provinces into smaller entities and by placing these under vicars. As a result, he was able to collect taxes more efficiently than was the case previously. It was thanks to this that he was able to finance the increased size of the armed forces and administration. The improved security provided by the enlarged military in its turn resulted in economic growth.

Constantine modified this structure by removing a significant proportion of the forces from the frontiers to form mobile field armies behind each sector of the frontier, which were used for offensive warfare. These forces were billeted in cities, which resulted in two developments. Firstly, the relationship between the civilians, who were forced to house the unruly soldiers, and the army worsened. Secondly, the billeting of the troops in cities brought with it wealth to those places where the men stayed. The latter undoubtedly more than compensated for the former. Constantine also reformed the military administration so that he created the offices of the Magister Equitum and Magister Peditum to serve as the highest ranking military officers and he abolished the Praetorian Guard so that the Praetorian Prefect became a civilian magistrate that could only occasionally be given military duties. Constantine was also the first emperor to delegate the entire administration of an area to the Praetorian Prefect so that he did not have an emperor above him. After Constantine, his sons divided the empire in three parts but in such a manner that there were four regional Praetorian Prefects in existence (Gaul, Italy, Illyricum, Oriens) and this system became permanent. The regional prefects were no longer tied to the emperor but to their regions so that they were responsible for the distribution of supplies for the local armies.

The military policies adopted by the different emperors always reflected their personality and the situation. Constantine followed aggressive and opportunistic military policies, but his sons varied their policies according to the situation and their personalities. The way in which the armies were deployed as well as the building of strong forts along the frontiers and fortified cities of the interior enabled the emperors: either 1) to stop the enemy invasions on the border; or 2) to employ the defence in depth approach when this was not possible; or 3) to use pre-emptive strikes; or 4) to use outright opportunistic invasions to annex new territories. Constantine had also brought a new dimension to the Roman foreign and military policies, which resulted from his conversion to Christianity. Henceforth the Roman Emperor would act as the defender of the faithful wherever needed and the conversion of the neighbours into Christianity became one of the principal goals of Roman foreign policy.¹

In 325/6 Constantine reformed his entire civilian and military administration to follow the system that he had apparently used in the west. In most cases Constantine changed only the names of the officials. The only real reform was the use of three parallel administrations (the Praetorian Prefecture, Comes of the Sacred Largesse, and Comes Rei Privatae) to control the provinces and the gathering of taxes. He also created the office of imperial Quaestor to prepare legislation and write responses to the petitions and letters sent to the emperor. The annona (taxes in kind to the soldiers) and other regular taxes were collected by the local city councils and the whole process was controlled by the administrations of the Praetorian Prefects. The Comes of the Sacred Largesse was responsible for the collections of the so-called donatives (money and bullion given to soldiers on special occasions paid by the middle class and rich). The Comes Rei Privatae collected the taxes/profits/rents from the lands and businesses owned by the emperor.

The most important organ of the state was the imperial Council (Consilium) which Constantine renamed the Consistory (Consistorium, later Sacred Consistory). The Consistory acted as a Council of the State where almost all important decisions of the state were made. The permanent members of the Consistory consisted of Mag.Off., Quaestor, and of the two counts of the finances: the Comes Sacrarum Largitonum, and Comes Rei Privatae. The magistri militum and other relevant personnel were called to attend when the council discussed military or diplomatic matters, while the PP and other relevant persons were invited to attend when the Consistory discussed legal or provincial matters. The Consistory usually included also personal friends of the emperor who did not have any official position in the administration, but who could wield considerable power behind the scenes thanks to their friendship. The official activities of the Consistory consisted of: 1) Military matters (revolts, military campaigns, diplomacy, conspiracies, military organisation, strategy etc.); 2) Religious matters (discussions of religious policy); 3) Nomination of dignitaries and members of the bodyguards; 4) Receiving of ambassadors. Depending upon the situation, the council invited the necessary staff and experts to attend the meeting. The permanent staff of the Consistory consisted of the silentiarii and decuriones (who ensured silence in the palace when the Consistory was in session), admissionales (who invited and introduced ‘guests’), and a secretis (secretaries of the Consistory), but other staff and experts could also be ordered to attend the meetings. The emperor usually made his decisions on the basis of the advice given by the council, but other persons (wife, relatives, and eunuchs of the bedchamber) could also influence his decisions.²

The diagram on the following page presents the administrative structure of the empire and should give readers an approximate overview of how the empire was administred and organised. It is based on diagrams of Delmaire and Haldon (2008) and probably includes elements that were introduced only later. It should be kept in mind, however, that the actual power structure was not and is not necessarily the same as the official one. It was and is possible for some persons to wield power far in excess of their official standing.

Intelligence Gathering

The Roman intelligence gathering network consisted of several overlapping organisations.

The principal purpose of these organisations was to secure the position and safety of the emperor and the safety of the empire. These organisations can be divided into military and civilian security forces.

The imperial bodyguards and their commanders formed the principal security apparatus of the ruler. In 361 the bodyguards consisted of the Protectores and of the units under their command. The Protectores were divided into the praesental Protectores Domestici and Protectores detached to the staffs of commanders. The Protectores and the Domestici were commanded by Comes Domestici or Comes Domestici Equites and Comes Domestici Peditum. Unfortunately, we do not know whether the office was divided in 361 even if there are signs that it was divided in 350 and we know that it was definitely divided in 395. The Comes or Comites served under the Magister Officiorum. The Protectores were detached to the headquarters staffs of the different officers/generals and in that capacity they acted as staff officers for the generals and at the same time acted as scouts, spies and assassins for the central government or for their commander.

The civilian branch of the intelligence network consisted of the agentes in rebus (couriers) and notarii (notaries, clerks) that were assigned to the staffs of high ranking civilians and officers. These two civilian groups (both organised according to military ranks and considered part of the military) could be used as spies, judges and assassins alongside their regular duties. Notably, both the agents and notaries were put under the command of Magister Officiorum, which means that Magister Officorum can be considered to have been a sort of spy master.

However, this was not the whole extent of the security apparatus operating under the emperor. He could also use any person he considered loyal to perform any mission he deemed necessary. In the capacity of Pontifex Maximus the emperors were also regularly kept abreast of what kind of questions were being asked from the oracles, astrologers and other soothsayers so that potential plots against the life of the emperor could be found out in a timely fashion. The members of the church also appear to have reported (as informers) to the emperor matters that had security implications.

In addition, the troops posted on the frontiers conducted active intelligence gathering missions and performed security functions when delegated to duty as guards in the forts, towers or when patrolling the roads, rivers and seas. The civilians also performed somewhat similar functions as guards and burgarii (see later) so that it was very difficult for anyone to pass unnoticed if one used roads or harbours.

Military

Since Ammianus states that Constantius II had not made any new innovations in the military structure, it is clear that in 361 the Roman military structures followed those created by Constantine the Great. His military structure consisted of the Protectores (imperial bodyguards), Comitatenses (Field Armies), Ripenses Milites (‘Riverine’ Legions, later Limitanei, i.e. border legions), alares (auxiliary cavalry on the frontiers, i.e. later Limitanei), and cohortales (auxiliary infantry along the frontiers, i.e. later Limitanei). The Protectores were commanded by the Comes or Comites Domesticorum (his/their superior was the civilian magistrate Magister Officiorum), the Comitatenses by the magistri equitum or peditum or comites (counts), and the Ripenses and auxiliaries on the frontiers by the duces (dukes) and comites (counts). One should also include among the most important refoms of Constantine the introduction of Christianity and Christian practices into the army so that the army became ever more Christianised as the century progressed. Despite the fact that Constantine the Great and other emperors increased the size of the armed force during the civil wars, it is probable that the overall size of the army after the conclusion of these wars was set close to what it had been under Diocletian so that there were about 255,000 men in the west and about 390,000 men in the east for a total of 645,000 men. However, this was not the entire armed strength of the empire for in addition to these there were the barbarian Federates and Laeti as well as the civilian paramilitary forces.

The navy was also presumably organised as before into river and seagoing fleets each under a prefect. The former were usually placed under the command of the local frontier commanders while the latter were usually placed under the magistri and acted as central reserves. The naval personnel presumably consisted of the same number of men as during the reign of Diocletian so that the fleets of the west had about 30,000 men and the eastern fleets about 46,000 men for a total of 76,000 men.

There are several unresolved problems regarding this organisation. Firstly, did the Protectores as a generic term also include the Scholae and other units (e.g. the Herculiani and Ioviani) commanded by the officers belonging to the Protectores-unit proper (probably about 300 men strong imperial staff college and bodyguard unit probably already called by the name of Protectores Domestici) and were they commanded by Comes Domesticorum in the field? Secondly, did the Comitatenses include units later called Palatini or were the Comitatenses just field armies commanded by the magistri equitum or peditum (Masters of Cavalry or Infantry) or comites so that at least some of the later Palatini units would have at this time belonged to the Protectores? Thirdly, when were the so-called Pseudo-Comitatenses (frontier units promoted into the Comitatenses) mentioned by the ND created? Fourthly, when did the Romans start to call those Comitatenses that were commanded by the magistri equitum and peditum in the emperor’s presence by the title Palatini? We simply do not know the definite answer to these and many other questions regarding the organisation, but I will present my best educated guesses on the following pages. For example, there is one piece of information which does suggest the probability that the Protectores were still used as a generic term for a larger group of elite troops consisting of several units commanded by the members of the actual Protectores all under Comes Domesticorum. This is clear from Ammianus’ referral to the use of Protectores under tribunes to protect all the vulnerable spots along the Euphrates against the Persians in 359. It is clear that Ammianus cannot have meant the small staff corps. Ammianus also mentions on several occasions that such elite units as the Scholae, Ioviani and Herculiani were commanded by the Comes Domesticorum (note the positions of Magnentius under Constans, and Barbatio under Gallus). See the first book in the series. In other words, I would suggest that the breaking up of the Protectores took place only after the reign of Constantius II under Julian.

At the time Julian had usurped power both he and Constantius had separate military administrations. This means that Julian had his own Magistri Equitum and Magister Peditum as well as Comes Domesticorum while Constantius had three magistri equitum (the highest ranking was Arbitio in emperor’s presence) and one Magister Peditum, and a Comes Domesticorum. This meant that Julian had to reorganise the command structure immediately after he had assumed the purple as sole emperor.

Constantine appears to have been the person responsible for the creation of the new unit ranks that are attested after his reign. These units consisted probably of the new units he created either out of recruits or from the men he had withdrawn from the frontier armies to create the Comitatenses. It is also probable that he made the unit structures of the former imperial Comitatus and Protectores to conform to this new system. We do not know whether he did the same for the units belonging to the frontier armies or auxiliaries, but the fact that there were no uniform unit sizes at the time the Strategikon was written in the sixth century suggests that the older units retained their old structures and hierarchies. The old legions of the imperial Comitatus such as the Ioviani and Herculiani appear to have retained their orginal strengths so that they consisted of about 5,000 footmen and about 726–800 horsemen as previously. However, it is still probable that even their internal structure was made to conform with the new system, which was based on Hellenistic military theory.

The following amended version of St. Jerome’s list of cavalry ranks is based on Bohec’s reconstruction (2006, 84–7) and it describes the ‘new’ cavalry bandon/tagma/vexillatio of Jerome’s era. According to Treadgold (1995, 89–91) and Bohec (2006, 84–7) it is likely that the new infantry ‘cohorts’ would also have had similar ranks. I have included my own additions and comments inside brackets.

tribunus (or Comes in the Strategikon)

primicerius (former highest ranking cav. centurion/ilarchês/vicarius; primus pilus of the 1st CO of inf.)

senator (former number 2 of the cav. centurions; princeps prior of the 1st CO)

ducenarius (commander of 200, former number 3 of the cav. centurions; hastatus prior of the 1 CO)

centenarius (former lowest ranking cav. centurion; princeps posterior and hastatus posterior of the 1st CO)

centenarius protector (former legionary 2-10 COs pili/triarii centurions)

centenarius ordinarius (former legionary 2-10 COs principes centurions)

centenarius ordinatus (former legionary 2-10 COs hastati centurions)

biarchus (former optio and highest ranking Decurion in the cav. and Decanus in the inf.?)

circitor (former cav. decurions or inf. decani ?)

semissalis (pentarchês, commander of five?)

eques (horseman)

pes (footman)

tiro (recruit)

In my opinion it is likely that the cavalry regiment described by Jerome had 512 horsemen (plus supernumeraries) while the equivalent infantry ‘regiment’ had 1,024 men (plus supernumeraries). The withdrawal of units from the frontiers seems to have resulted in the creation of legions that consisted of two 1,024-man regiments each under a tribune so that the 2,048-man new legion was commanded by a comes. The fact that the forts built along the frontiers were designed to house 2,000–3,000 men suggests that most of the ‘Limitanei’ legions left along the borders also had about 2,000 men. The old auxiliary units along the borders presumably retained their approximate strengths of 500 or 1,000 men. The newer auxilia (later called auxilia palatina) that formed part of the praesental army under the magistri (or the Protectores?) appear to have operated as pairs so that the pair (2 x 512) probably consisted of about 1,024 men, but since the different units of auxilia (‘medium infantry’) were probably formed by different emperors we do not know whether all of the units conformed to this model. The light infantry proper appears to have been formed into 1,024-man units (plus supernumeraries) so that with the addition of the heavy-armed (including the later auxilia palatina) it was possible to form divisions (formerly called legions, later mere) of 6,000–7,000 men (e.g. consisting of 4,096 heavyarmed and 2,048 light-armed).

For combat purposes the old and new units were organised in various sizes just as the detachments and units had been before so that it is probable that the system followed the same practices as later described in the Strategikon, i.e. the cavalry units were to be divided into entities of perhaps about 500 men (at the time the Strategikon was written to ‘banda’ of 200 to 400 men) which were then grouped together to form about 2,000–3,000 strong ‘moirai’, and the ‘moirai’ in their turn were grouped together to form about 6,000–7,000 mere (divisions = legions). The organisation of the infantry units would have followed similar principles. The width of each of the units could also be adjusted by making the units either deeper or shallower.

Cavalry and Cavalry Tactics

³

The cavalry consisted of five basic types. The first was the traditional Romano-Gallic-Spanish cavalry armed with a shield, helmet, sword, and javelin(s) or spear(s). The horses of this type of cavalry were usually unarmoured, but could also have chamfrons and side-coverings. They were also taught to use slings, crossbows and composite bows after the reign of Hadrian. The second consisted of the mounted archers that were mostly recruited from the easterners. The third consisted of the super heavy cavalry that consisted of two basic types: 1) the cataphracts (man fully armoured, but the horse wore only frontal armour; the rider armed with a spear, shield, sword and possibly with a bow); 2) the new clibanarii of Constantius II (man and horse fully armoured; rider armed with a contus, sword and bow) who did not use shields. The fourth type was the cavalry lancer riding on an unarmoured horse who was equipped like a Sarmatian contarius or Arabic lancer. The fifth group were the extra light Moorish cavalry that fought with javelins. All of these different types of cavalry used different horse breeds suited to their particular role that were supplied by the imperial stud-farms, or paid for by taxpayers, or bought. The unit formation of the cavalry depended upon the type of unit and situation so that the units were deployed either as rank and file squares/oblongs (the standard formation with depths varying between five and ten ranks according to the quality of the unit; used by all types of units), or as wedges (small ‘skirmishing’ wedge), or as rhomboids (at least the Armenian, Parthian and Sasanian units), or as irregular throngs (droungoi/globi used by all units when necessary). The super heavy cavalry could also use the massive ‘regimental’ wedge for the breaking up of the enemy infantry formation. For additional details concerning the various types of cavalry see the chapter Enemies.

Valerius Maxantius, Numerus Catafractariorum, 4th century

AD

(Worms) On the basis of the presence of chiselled large holes in the armour, I have made the educated guess that Valerius was equipped with chain mail armour, which I have ‘emended’ to the illustration with dots. This same style of armour was later recommended by the 6th century Strategikon. It also clearly resembles the mail armour worn by the Avar/Bulgar on the right. Note also the way in which Valerius holds the contus-spear. His grip clearly resembles the couched lance technique, and in fact, I would suggest that the Roman heavy cavalry did use this technique with the horned saddle. This is not the only extant work of art showing this same grip from this era! The fact that the lance is not tucked in the armpit has resulted from the artistic conventions. Even though it is possible to tuck the lance against the side, the most natural way to hold the lance is still to tuck it in the armpit, e.g. none of the Normans using the couched lance technique in the Bayeux Tapestry has the lance tucked in the armpit. All show it in the same manner as shown in the Valerius illustration. In short, the Roman cavalry used their spears in four basic ways each of which had different variations: 1) over-the-shoulder technique used mainly for throwing; 2) underarm technique used for thrusting from below; 3) couched lance technique for shock; 4) various types of two-handed grips with the heavy contus for shock. However, it is possible that the couched lance technique was subsequently phased out in the course of the 5th century as a result of the adoption of the more modern saddle with the stirrups. Note also that Valerius rides a stallion, which does suggest the use of the stallion’s aggression in a cavalry charge.

Avar or Bulgar horseman, 8th century.

I have simplified the mail armour worn by the rider for the sake of ease of drawing so that instead of the rings, the illustration has dotted lines (word-art). Note the resemblance of the armour to the armour worn by Valerius. The same illustration (the captive) also proves that the so-called lamellar armour could be worn similarly. I would suggest that one should reconstruct/emend Valerius’ hands and feet to wear a similar type of splinted protection. Note also that the Roman horsemen used similar head-hunting to prove their manhood as can be witnessed for example from Trajan’s Column and Constantine’s Arch.

Fully emended Valerius illustration as cataphract in readiness for combat.

A member of the elite scouting unit, explorator Respectus. Note the light equipment that resembles the equipment worn by the Moorish cavalry units.

The cavalry was used for a great variety of missions. Firstly, the cavalry was used for scouting, skirmishing and pursuit, or as an anti-guerrilla/bandit force. Secondly, it could be deployed as an independent army, but in contrast to the third century this was rare during this period. Thirdly, it could be deployed alongside infantry to support it. Despite the fact that the Romans usually employed mixed armies of infantry and cavalry, the cavalry usually decided the battles, either outright by being deployed as vanguard for the army, or by outflanking the enemy.

When deployed separately or as a vanguard, the standard Roman cavalry formation consisted of two lines, the second of which served as a reserve. This formation was always surrounded by scouts and patrols.⁴ The large cavalry force (over 12,000 men) was deployed so that the first line consisted of three divisions and wing units on both sides to protect the flanks or to outflank the enemy; and of the second line of four divisions and fill-up units which were deployed as two ranks deep between them to ensure that the distances remained the same. The ‘third line’ was used as a rear guard. If the cavalry force consisted of 5,000–15,000 men, the standard deployment called for only two reserve divisions and the rear guard. When there were less than 5,000 men the second line was to consist of only one reserve division. In practice, however, the Romans appear to have still varied their formations greatly so that the number and deployment of reserve units varied.

The Romans divided the larger cavalry divisions into separate units of koursores (runners/skirmishers) and defensores (defenders). The koursores formed the flanks of the division and were used for skirmishing and pursuit in irregular order (droungos). The defensores that maintained close order (width of file c. 1m and depth of rank c. 4–5 m) formed the centre of the division. They protected the koursores if they needed to retreat by attacking the pursuers. If the Romans decided that it would be advantageous to charge immediately, they did not send the koursores to skirmish, but attacked immediately so that all units were deployed in close order. If the attack was successful, the koursores pursued the enemy in irregular order. The Romans varied their tactics according to the situation: if the Romans outnumbered the enemy, they enveloped its flanks; if they had slightly more men or had equal numbers of men, they attempted to outflank the enemy with one wing (usually with their right wing against the enemy’s left wing); if the Romans were outnumbered, they sent their centre forward first and the flanks only after that. The second line supported the first if the front line or its divisions were forced to flee so that the units of the second line charged against the pursuers.

Infantry

⁶

The infantry consisted of three basic types: the fully-equipped heavy infantry (legionaries/hoplites); the medium infantry (auxiliaries, auxilia palatina, peltasts); the light infantry (psiloi). It is also possible that the Romans employed a fourth composite type of heavy infantry armed with bows for which there is evidence in Vegetius and Peri Strategikes. The specialist clubmen/mace-wielders would have been the fifth group.

The typical equipment of the late fourth century legionary consisted of the mail or scale armour (or muscular armour and in some cases even of the lorica segmentata); helmets of several different types (mainly ridge or Spangen helmets: e.g. Deurne, Intercisa, Berkasovo etc.) the most common being the ‘ridge helmets’; an oval, round, or rectangular shield; a spear (c. 2.5–3.74 m in length); a heavy javelin (c. 1.9–2.5 m in length); a short javelin (several types including lancea, verrutum etc.); a spatha (a long double-edged sword); a gladius/semispatha (a short double-edged sword) meant for close quarters infantry fighting; and a dagger or knife. See the Photo Section! Many of the units also carried about five weighed darts called mattiobarbuli (or plumbata) inside their shields that were used for throwing. At least a quarter or a third of them was also trained to use bows and all were trained to throw stones by hand or by sling.⁵ In addition to these, there were also specialist units of auxiliaries, allies or mercenaries to perform these functions, but if there were not enough of these available, it was the duty of the specially selected and trained legionaries to perform the long-range combat at the beginning of a battle. The illustrations of shields support the use of three different types of grips/handles. Firstly, there were the shields with the handle behind the boss that were used in the traditional manner for shield bashing in sword fighting. Secondly, there are also illustrations of the hoplite style grip for the shields. The use of this type of shield suggests the use of the othismos (mass shoving with bended knees like in a rugby match) at close quarters fighting as well the use of the hoplite style spear thrusting. It is in fact quite possible that both styles were in use at the time. The third type had both grips.

The auxiliary medium infantry was equipped with helmets, spears, spatha-swords, and shields, but usually lacked armour. They did sometimes use ‘ersatz’ armour consisting of padded coats or leather armour etc. The same could also be true of the heavy infantry if they were equipped lightly for duty in difficult terrain (e.g. forests and mountains). The lack of armour undoubtedly made these men vulnerable to being hit by missiles or other weapons, but in combat situations fighting spirit was more important than the amount of armour worn. It was quite possible for the medium infantry to defeat any type of unit in combat.

There were also units of special club-wielders or mace-wielders that were used against the cataphract cavalry. These men were used either in front of the infantry phalanx to break up the enemy charge or behind the phalanx when it was opened up to admit the cataphracts through so that the clubmen could pummel them unconscious. This type of superbly brave warrior could be really lightly equipped as the Germanic clubmen in Trajan’s and Theodosius’ Columns prove. They needed the mobility to avoid being trampled by the horses. See the illustrations. The lancearii (served possibly as a model for the 10th century menaulatoi) also appear to have been posted in front of the phalanx either to harass the enemy or to break up the enemy cavalry charge. The Romans could also post a separate detachment of spearmen and light infantry in front of the phalanx in a wedge formation to break up the attack of the enemy cavalry.

The light infantry consisted of the javelin throwers, slingers and archers. All of these could carry small shields and some sort of swords, but the use of armour and helmets depended upon the unit. The light-armed were particularly useful in difficult terrain and in sieges, and could defeat any type of force in the right circumstances; in other words, if the terrain, fortifications or heavy-armed gave them enough protective cover from which to pepper the enemy with missiles. The slingshots were particularly useful against armoured horsemen because it was practically impossible to see them from a moving horse.

Infantry Tactics (see the photo inset in the plates for examples of equipment)

Roman infantry tactics were based on the use of the different variants of the phalanx formation. The principal variant was the lateral phalanx with cavalry wings. This formation had three basic forms depending on the size of the army and whether the baggage train accompanied the army. If they had less than 24,000 men, they divided the phalanx into three divisions (probably about 4,000 heavy-armed and 2,000 light-armed per division, the rest being designated as reserves), and if they had more than 24,000 men the phalanx was divided into four divisions. The various units and detachments were united or divided as needed to achieve these divisions. If the army had left its baggage train in the marching camp or city, the Romans used a double phalanx to protect the rear.

The heavy/middle infantry phalanx consisted of ranks and files with varying depths (4, 8, 16 and in exceptional cases 32) while the light infantry was deployed either in front, behind, in the middle or on the flanks as required by the tactical situation. The four-deep array was the shallowest formation that made the phalanx as wide as possible but was too shallow to allow its division into two lines. The deeper formations enabled the the Romans to divide their units to face front and rear simultaneously (amfistomos phalanx, orbis) or to separate the rear portion into a separate line and form a double phalanx (difalangia, duplex acies). It was also possible to form the double phalanx by designating separate units one after another e.g. by posting one line of cohorts or legions in front followed up by a line of other cohorts or legions.

The cavalry units posted on the flanks were usually deployed in close order formation with depths varying from 5 to 10 ranks according to the availability of horsemen and quality of unit. The super heavies could also be deployed in the middle to break up the enemy infantry formation. The irregular types of cavalry could also employ their specialist unit orders (small wedge, rhombus, droungos) and skirmishing tactics on the flanks. The Romans usually posted separate reserves behind, or in between the phalanxes if the formation was a double phalanx, consisting of both infantry and cavalry. The reserves were usually posted behind the wings and centre, or where needed. If the Romans had not left their baggage train behind, they stationed it a bowshot behind the infantry force to protect the rear of the formation. The drivers were expected to support the guards left behind with javelins, bows, slings, caltrops and metal darts. The wagons could also be covered by cloth to protect the drivers and the oxen against arrows. The Romans also placed batteries of field artillery mounted on carts among the wagons to shoot over the head of the army, or to shoot at the enemy (e.g. elephants) that had managed to get through the phalanx, or to protect the rear against possible outflanking attempts by the enemy. The following illustrations show two possible variants of the lateral phalanx.

Two variants of lateral phalanx with reserves not in scale (there were also other variants depending upon the size of the army, the placing of the reserves, and deployment of the light infantry)

Over 24,000 footmen deployed as double phalanx when the baggage train did not accompany the army. Light infantry shown by the boxes without lines. Light infantry in irregular groups could also be posted on the flanks to make the formation a square.

Lateral phalanx with less than 24,000 footmen with the baggage line and artillery carts (the black line). The light infantry posted on the flanks between the heavy infantry and cavalry. This tactic enabled the Romans to use their light infantry against enemy cavalry and infantry simultaneously and also lengthened the line.

The lateral phalanx tactics followed the same principles as the cavalry tactics: if the Romans outnumbered the enemy and/or had a longer line, the lateral phalanx was used to outflank the enemy on both flanks; if the Romans outnumbered the enemy only slightly or had only a slightly longer line, they outflanked it only on one flank; if the Romans had equal or smaller numbers, they attempted to break the enemy’s centre with an infantry wedge formed in the middle while they used various defensive techniques to protect their flanks (cavalry skirmishing, reserves to block the enemy attack, double front by the flank units against outflanking, double phalanx by flank units, light infantry to block outflanking, etc.). In order to achieve this ability to manoeuvre the units in combat, the soldiers were taught to thin their lines (the formation widened as every other man stepped to form a new file), to thicken the lines (they deepened and shortened the line as files were inserted into other files), to countermarch, to wheel, to turn in place and so forth. These very same manoeuvres also enabled the soldiers to form the different grand tactical variations of the phalanx.

The Romans used a great variety of unit/divisional combat manoeuvres that included the use of: a line to engage the enemy by its front; a wedge (cuneus) to crush and penetrate the enemy formation; a hollow wedge/pincer/scissors (forceps) to crush an enemy infantry wedge; a saw (serra), which consisted of units advancing and retreating that was used to harass the enemy; the circle (amfistomos falanx/orbis), which was a double fronted array used to protect the unit against outflanking; the use of separate and independent infantry or cavalry detachments (globus/droungos); the use of the antistomos difalangia (facing double phalanx) to open up a route for the enemy cavalry wedge or elephants to penetrate through so that it could be crushed in between the phalanxes or be destroyed by the field artillery posted behind. A crescent or forward-angled half-square by individual unit or units could be used to outflank an opposing enemy unit. A separate wedge of infantry (probably consisting of club-bearers, lancearii, spearmen, light-armed) could also be sent in front of the phalanx to break up an enemy cavalry charge and individual units could outflank separate individual enemy units. For some instances of the use of these, see the narrative.

The principal battlefield unit tactic of the legionaries and auxiliaries (armed with melee weapons) against enemy infantry was to advance first within the range of arrows. There under the cover of the protective fire from the light-armed, they would place their shields in an offensive testudo/foulkon array (tortoise array with a shield roof, with file widths of 45–65cm) and advance to the range of the plumbata/mattiobarbuli. If all men were fully armoured, it was also acceptable to advance in the less tight attack formation (c. 80–90cm per man in width) without a shield roof, but for obvious reasons the men preferred the safety of the shield roof even in the looser version. At that point, the soldiers would throw their mattiobarbuli, after which they advanced to the range of javelins, and threw the spear or javelin with a jump, and then drew the spathae or gladii depending upon the situation, after which they ran forward to attack with the swords by using thrusts and cuts at short range. The gladius was more suited to infantry combat while the spatha was better against cavalry. The second rank supported the first with spear thrusts. The offensive testudo was an infantry array used against infantry and fortifications in which the front rankers tightened the array so that their shields interlocked rim-to-boss in front and the rear rankers placed their shields above their heads. The aim of the volley(s) of missiles was to cause casualties among the enemy and to render shields useless all of which the Roman swordsmen could exploit when they charged forward. At close range, the legionary used his shield and shield boss for bashing and pushing and his sword for thrusts and cuts. The advantage of this tactic was that it aroused the aggressiveness of the men and frightened the enemy. An alternative tactic was to stay in place and wait for the enemy to approach. This tactic had two advantages: the combat line would be perfectly aligned; and the men were rested. If the battlelines were stationary, sometimes bold individuals also charged out of the formation to engage the enemy and thereby gave an example to the rest. If needed the legionaries could also wield axes, mattocks, poles and pitchforks.

Against cavalry the Romans usually adopted the defensive version of the testudo/foulkon, which consisted of the front rankers kneeling and placing their shields rim-to-rim and by resting the butt of their hasta-spear (when equipped properly for the situation) or javelin against the ground, while the second rank crouched a little and interlocked the bottoms of their shields above the tops of the shields of the front rankers, and the third rankers did the same while standing up as did the fourth rank. The 2nd to 4th rankers held their hastae (or other shafted weapons) like javelins and pointed those towards the enemy while the men behind threw javelins or darts or shot arrows. When the multipurpose heavies faced cavalry, the first three ranks rested their spears on the ground; the first two ranks aimed their bowshots at the horses, and the third (and others with bows behind them) shot at a higher angle so that the arrows dropped on the enemy from above. When the enemy approach had been slowed down by the barrage of arrows, the three front ranks picked up their spears and with the fourth rank they formed up a wall of spears and engaged the enemy.

Unlike the usual assumption, phalangial tactics were very versatile because they did not consist solely of the lateral phalanx but in truth included numerous different unit tactics (e.g. a single unit could use a crescent or forward-angled half-square to surround approaching enemy cavalry) and grand tactical formations. These different grand tactical formations included the following: the oblique formation against one of the enemy flanks to crush it, when the enemy outnumbered the Romans; the lengthening of the phalanx while one or both flanks advanced against the enemy flanks (a variant consisted of the sending of the light-armed in front to protect the advancing wings), which was one of the variant forms of the so-called epikampios emprosthia of the Hellenistic military theory; the epikampios emprosthia (forward angled half-square) proper to outflank the enemy; the crescent to outflank the enemy; the convex to engage the enemy centre while the wings were held back; the epikampios opisthia (rearward angled half-square) to protect the flanks; the various different arrays exploiting the terrain obstacles either to protect the flank or flanks; the hollow square/oblong that was used both as as a fighting and marching formation; wheeling of the flanks as needed.

As I noted in my doctoral dissertation back in 2004 (Age of Hippotoxotai), the hollow square the Byzantines used in the 10th century was ancient in origins. As we shall see, the hollow square in its various forms became the standard array for the Roman army after c. 367. On the basis of later and period evidence (see the narrative), the two principal variants of the hollow square consisted of either 12 or 16 taxiarchies. Historians have so far failed to recognise the smaller variant mainly because the 16 taxiarchies were also organised as 12 units when the corner units were in contact with each other. However, the Peri katastaseôs aplektôu (1, 6, 8) makes it clear that there also existed a smaller variant with a mere 12 taxiarchies (two ‘gates’ per side). The organisation of the different sections/taxiarchies within this array could be varied. There was only one constant which was the placing of the heavy infantry ‘hoplites’ at the outer edges, but when the Romans retreated before cavalry forces, they usually placed archers on the outside.

The light infantry was usually placed behind the heavy infantry, but the more secure version placed additional heavy infantry ranks behind the light infantry so that each unit could face both forwards and backwards if necessary – this provided protection for each unit, if the enemy managed to penetrate inside the square. The surplus light infantry and especially the javeliners were placed behind each of the intervals of the square or in line with the front ranks to protect these against enemy attacks. During marching the light-armed could also be placed outside the square to protect the array with missiles against harassment. If hard-pressed they could retreat inside the square. The light-armed could also precede the army to harass the enemy or be used in support of the cavalry. The illustration below shows the standard hollow square version preserved in the Byzantine Interpolation of Aelian. This kind of array could also be formed so that the corner divisions consisted of only one unit divided, but as said in the variant provided by the PKA, this was not the case.

During marching, most of the cavalry was placed outside and could be used to engage the enemy. The van consisting of the so-called prokoursatores (front-runners) was placed always in front to reconnoitre and to engage careless enemies. The cavalry placed behind it was used to protect and support them. If the vanguard and the cavalry placed outside were hard-pressed they withdrew inside the square. When inside the square the cavalry sallied out from one side against the enemy while other units sallied out from the other sides to outflank the enemy. If the enemy had infantry and the cavalry was unable to defeat them, the light-armed were sent in support, and if this did not work, then the heavy-armed infantry moved to the attack, which meant the advance of one flank of the square so that the rest of the forces (the other three flanks, light-armed and cavalry) were used in its support as required by the situation.

The shape of the square array was always adapted to