Byzantine army The Byzantine army or Eastern Roman army was the primary military body of the Byzantine armed forces , serving alongside the Byzantine navy . A direct descendant of the Roman army , the Byzantine army maintained a similar level of discipline , strategic prowess and organization . It was among the most effective armies of western Eurasia for much of the Middle Ages . The early Byzantine army experienced victory , as well as defeat , and over time the cavalry arm became more prominent as the legion system disappeared in the early 7th century . Later reforms reflected some Germanic and Asian influences – rival forces frequently became sources of mercenary units e . g . ; Huns , Cumans , Alans and ( following the Battle of Manzikert ) Turks meeting the Empire ' s demand for light cavalry mercenaries . Since much of the Byzantine military focused on the strategy and skill of generals utilizing militia troops , heavy infantry were recruited from Frankish and later Varangian mercenaries . From the seventh to the 12th centuries , the Byzantine army was among the most powerful and effective military forces – neither Middle Ages Europe nor ( following its early successes ) the fracturing Caliphate could match the strategies and the efficiency of the Byzantine army . Restricted to a largely defensive role in the 7th to mid - 9th centuries , the Byzantines developed the theme - system to counter the more powerful Caliphate . From the mid - 9th century , however , they gradually went on the offensive , culminating in the great conquests of the 10th century under a series of soldier - emperors such as Nikephoros II Phokas , John Tzimiskes and Basil II . The army they led was less reliant on the militia of the themes ; it was by now a largely professional force , with a strong and well - drilled infantry at its core and augmented by a revived heavy cavalry arm . With one of the most powerful economies in the world at the time , the Empire had the resources to put to the field a powerful host when needed , in order to reclaim its long - lost territories . After the collapse of the theme - system in the 11th century , the Byzantines grew increasingly reliant on professional Tagmata troops , including ever - increasing numbers of foreign mercenaries . The Komnenian emperors made great efforts to re - establish a native army , instituting the " pronoia " system of land grants in exchange for military service . Nevertheless , mercenaries remained a staple feature of late Byzantine armies since the loss of Asia Minor reduced the Empire ' s recruiting - ground , while the abuse of the " pronoia " grants led to a progressive feudalism in the Empire . The Komnenian successes were undone by the subsequent Angeloi dynasty , leading to the dissolution of the Empire at the hands of the Fourth Crusade in 1204 . The Emperors of Nicaea managed to form a small but effective force using the same structure of light and heavily armed troops , both natives and foreigners . It proved effective in defending what remained of Byzantine Anatolia and reclaiming much of the Balkans and even Constantinople itself in 1261 . Another period of neglect of the military followed in the reign of Andronikos II Palaiologos , which allowed Anatolia to fall prey to an emerging power , the Ottoman emirate . Successive civil wars in the 14th century further sapped the Empire ' s strength and destroyed any remaining chance of recovery , while the weakening of central authority and the devolution of power to provincial leaders meant that the Byzantine army was now composed of a collection of militias , personal entourages and mercenary detachments . History . Just as what we today label the Byzantine Empire was in reality and to contemporaries a continuation of the Roman Empire , so the Byzantine army was an outgrowth of the Late Roman structure , which largely survived until the mid - 7th century . The official language of the army for centuries continued to be Latin but this would eventually give way to Greek as in the rest of the Empire , though Latin military terminology would still be used throughout its history . In the period after the Muslim conquests , which saw the loss of Syria and Egypt , the remainders of the provincial armies were withdrawn and settled in Asia Minor , initiating the thematic system . Despite this unprecedented disaster , the internal structures of the army remained much the same , and there is a remarkable continuity in tactics and doctrine between the 6th and 11th centuries . The Battle of Manzikert in 1071 and the subsequent Seljuk invasions , together with the arrival of the Crusades and the incursions of the Normans , would severely weaken the Byzantine state and its military , which increasingly had to rely on foreign mercenaries . The army under Diocletian and Constantine . The Eastern Empire dates from the creation of the Tetrarchy ( " Quadrumvirate " ) by the Emperor Diocletian in 293 . His plans for succession did not outlive his lifetime , but his reorganization of the army did by centuries . Rather than maintain the traditional infantry - heavy legions , Diocletian reformed it into " limitanei " ( " border " ) and " comitatenses " ( " field " ) units . There was an expansion of the importance of the cavalry , though the infantry still remained the major component of the Roman armies , in contrast to common belief . In preparation for Justinian ' s African campaign of 533 - 534 AD , the army assembled amounted to 10 , 000 foot soldiers and 5 , 000 mounted archers and federate lancers . The " limitanei " and " ripenses " were to occupy the " limes " , the Roman border fortifications . The field units , by contrast , were to stay well behind the border and move quickly where they were needed , whether for offensive or defensive roles , as well as forming an army against usurpers . The field units were held to high standards and took precedence over Limitanei in pay and provisions . Cavalry formed about one - third of the units , but as a result of smaller units , about one - quarter of the Roman armies consisted of cavalry . About half the cavalry consisted of heavy cavalry ( including the " stablesiani " ) . They were armed with spear or lance and sword and armored in mail . Some had bows , but they were meant for supporting the charge instead of independent skirmishing . In the field armies there was a component of some 15 % of cataphract arii or clibanarii , heavily armoured cavalry who used shock tactics . The light cavalry ( including the " scutarii " and " promoti " ) featured high amongst the limitanei , being very useful troops on patrol . They included horse archers ( " Equites Sagittarii " ) . The infantry of the " comitatenses " was organized in regiments ( variously named " legiones " , " auxilia " or just " numeri " ) of about 500 – 1 , 200 men . They were still the heavy infantry of old , with a spear or sword , shield , body armour and a helmet . But now each regiment was supported by a detachment of light infantry skirmishers . If needed , the infantry could take off ( some of ) their armour to act in a more flexible way as Modares did ( according to Zosimus ) during the Gothic War of the 370s . The regiments were commanded by a " tribunus " ( " tribune " ) and brigaded in pairs ( cavalry units did , too ) under a " comes " . These brigades probably were tactical and strategic units only , as no traces survive of brigade staff corps . On the other hand , little is known of the limitanei . The old legions , cohort s and cavalry ala e survived there , and newer units were created ( the new legions , or " auxilia " and " vexillatio nes " , amongst the cavalry . The limitanei infantry may have been lighter - equipped than the comitatenses infantry , but there is no evidence whatsoever . They were paid less than the field troops and recruited locally . Consequently , they were of inferior quality . However , they were in the line of fire . They countered most incursions and raids . Thus , it can be assumed they did have superior field experience ( except in periods of long campaigning for the comitatenses ) , though that experience did not extend to large battles and sieges . The " Scholae Palatinae " units , which were more properly known as the " Schola Protectores Domestici " and the " Protective Association of the Royal Escort " ( also called the " Obsequium " ) , were the personal guard of the Emperor , and were created to replace the Praetorian Guard disbanded by Constantine I . Following a major reorganisation of the Roman army during the Emperor Diocletian ' s reign ( 284 - 305 AD ) the legions in the third and fourth century bore little resemblance to those of the Republic or earlier Roman empire . Reduced in numbers to about 1 , 000 men per legion , these units became static garrison troops , sometimes serving on a part - time militia basis as hereditary " limitanei " . As such they were separate from the new mobile field army . The army of Justinian I and his successors . The following is drawn mainly from J . B . Bury ' s History of the Later Roman Empire : From the Death of Theodosius I to the Death of Justinian I ( London , 1923 ; Dover Publications reprint , 1958 ) . The army of Justinian I was the result of fifth - century reorganizations to meet growing threats to the empire , the most serious from the expanding Persian empire . Gone were the familiar legions , cohorts and alae of old Rome , and in their place were small infantry battalions or horse regiments called a tagma or numerus . A tagma had between 300 and 400 men and was commanded by a tribune . Two or more tagmata formed a brigade , or moira ; two or more brigades a division , or meros . There were six classifications of troops . Modern scholars estimate the total strength of the imperial army under Justinian to be between 300 , 000 and 350 , 000 soldiers . Field armies generally had 15 , 000 to 25 , 000 soldiers and were formed mainly of comitatenses and foederati , reinforced by the commanders ' retinues and barbarian allies . The expeditionary force of Belisarius during his reconquest of Carthage from the Vandals in 533 is illustrative . This army had 10 , 000 comitatenses and foederati infantry , with 3 , 000 similarly composed cavalry . There were 600 Huns and 400 Herules , all mounted archers , and 1 , 400 or 1 , 500 mounted bucellarii of Belisarius ' retinue . The small force of less than 16 , 000 men voyaged from the Bospherus to North Africa on 500 ships protected by 92 dromons , or war - ships . Tactics , organization and equipment had been largely modified to deal with the Persians . The Romans adopted elaborate defensive armor from Persia , coats of mail , cuirasses , casques and greaves of steel for tagma of elite heavy cavalrymen called cataphracts , who were armed with bow and arrows as well as sword and lance . Large numbers of light infantry were equipped with the bow , to support the heavy infantry known as scutarii ( shield men ) or skutatoi . These wore a steel helmet and a coat of mail , and carried a spear , axe and dagger . They generally held the center of a Roman line of battle . Infantry armed with javelins were used for operations in mountain regions . Notable military events during the reign of Justinian included the battle of Daras in 530 , when Belisarius , with a force of 25 , 000 , defeated the Persian emperor ' s army of 40 , 000 . In addition to his reconquest of Carthage , noted above , Belisarius also recaptured Sicily , Naples , Rome and the rest of Italy from the Goths in a war lasting from 536 to 540 . Another famous commander of the time was the imperial eunuch Narses , who defeated a Gothic army at Busta Gallorum on the eastern coast of Italy in 552 . The armies of the middle Byzantine period , 7th – 11th centuries . The " Themata " . The " thema ta " ( Gr . θέματα ) were administrative divisions of the empire in which a general ( Gr . στρατηγός , " strategos " ) exercised both civilian and military jurisdiction and a Judge ( Κριτής του Θέματος , " Krites tou thematos " ) held the judicial power . The name is peculiar ; Treadgold ' s closest guess is that thema was being used to denote " emplacements " . Modern historians agree that the designations of the first themes came from the field armies that were stationed in Asia Minor . The five original themata were all in Asia Minor and originated from the earlier mobile field armies . They were : Within each theme , eligible men were given grants of land to support their families and to equip themselves . Following revolts strengthened by the large size of these divisions , Leo III the Isaurian , Theophilus , and Leo VI the Wise all responded by breaking the themes up into smaller areas and dividing control over the armies within each theme into various " tourma i " . The large early themes were progressively split up in the 8th – 9th centuries to reduce their governors ' power , while in the 10th century , new and much smaller themes , called " Armenian themes " because many were settled by Armenians , were created in the East in conquered territories . While in ca . 842 the " Taktikon Uspensky " lists 18 " strategoi " of themes , the " De Thematibus " of ca . 940 lists 28 , and the " Escorial Taktikon " , written ca . 971 – 975 , lists almost 90 " strategoi " of themes and other military commands . Sicily had been completely lost to the expanding Emirate of Sicily at the beginning of Constantine VII ' s reign in 905 and Cyprus was a condominium jointly administered with the Abbasid Caliphate until its reconquest by Nikephoros II Phokas in 965 . Constantinople itself was under an Eparch and protected by the numerous " tagmata " and police forces . Under the direction of the thematic " strategoi " , " tourmarchai " commanded from two up to four divisions of soldiers and territory , called " tourma i " . Under them , the " droungarioi " headed subdivisions called " droungoi " , each with a thousand soldiers . In the field , these units would be further divided into " banda " with a nominal strength of 300 men , although at times reduced to little more than 50 . Again , the fear of empowering effective revolts was largely behind these subdivisions . The following table illustrates the thematic structure as found in the Thracesian Theme , circa 902 – 936 . The Imperial " tagmata " . The " tagmata " ( τάγματα , " regiments " ) were the professional standing army of the Empire , formed by Emperor Constantine V after the suppression of a major revolt in the Opsician Theme in 741 – 743 . Anxious to safeguard his throne from the frequent revolts of the thematic armies , Constantine reformed the old guard units of Constantinople into the new " tagmata " regiments , which were meant to provide the emperor with a core of professional and loyal troops . They were typically headquartered in or around Constantinople , although in later ages they sent detachments to the provinces . The " tagmata " were exclusively heavy cavalry units and formed the core of the imperial army on campaign , augmented by the provincial levies of thematic troops who were more concerned with local defense . The four main " tagmata " were : There were also auxiliary " tagmata " , such as the " Noumeroi " ( Gr . Νούμεροι ) , a garrison unit for Constantinople , which probably included the regiment " of the Walls " ( Gr . τῶν Τειχέων , " tōn Teicheōn " ) , manning the Walls of Constantinople . , and the " Optimatoi " ( Gr . , " the Best " ) , a support unit responsible for the mules of the army ' s baggage train ( the τοῦλδον , " touldon " ) . There was also the " Hetaireia " ( Gr . , " Companions " ) , which comprised the various mercenary corps in Imperial service , subdivided in Greater , Middle and Lesser , each commanded by a " Hetaireiarchēs " In addition to these more or less stable units , any number of shorter - lived tagmata were formed as favoured units of various emperors . Michael II raised the " Tessarakontarioi " , a special marine unit , and John I Tzimiskes created a corps called the " Athanatoi " ( Gr . Ἀθάνατοι , the " Immortals " ) after the old Persian unit . The army during the Komnenian dynasty . Establishment and successes . At the beginning of the Komnenian period in 1081 , the Byzantine Empire had been reduced to the smallest territorial extent in its history . Surrounded by enemies , and financially ruined by a long period of civil war , the empire ' s prospects had looked grim . Yet , through a combination of skill , determination and years of campaigning , Alexios I Komnenos , John II Komnenos and Manuel I Komnenos managed to restore the power of the Byzantine Empire by constructing a new army from the ground up . The new force is known as the Komnenian army . It was both professional and disciplined . It contained formidable guards units such as the Varangian Guard and the Immortals ( a unit of heavy cavalry ) stationed in Constantinople , and also levies from the provinces . These levies included cataphract cavalry from Macedonia , Thessaly and Thrace , and various other provincial forces from regions such as the Black Sea coast of Asia Minor . Under John II , a Macedonian division was maintained , and new native Byzantine troops were recruited from the provinces . As Byzantine Asia Minor began to prosper under John and Manuel , more soldiers were raised from the Asiatic provinces of Neokastra , Paphlagonia and even Seleucia ( in the south east ) . Soldiers were also drawn from defeated peoples , such as the Pechenegs ( cavalry archers ) , and the Serbs , who were used as settlers stationed at Nicomedia . Native troops were organised into regular units and stationed in both the Asian and European provinces . Komnenian armies were also often reinforced by allied contingents from the Principality of Antioch , Serbia and Hungary , yet even so they generally consisted of about two - thirds Byzantine troops to one - third foreigners . Units of archers , infantry and cavalry were grouped together so as to provide combined arms support to each other . This Komnenian army was a highly effective , well - trained and well - equipped force , capable of campaigning in Egypt , Hungary , Italy and Palestine . However , like many aspects of the Byzantine state under the Komnenoi , its biggest weakness was that it relied on a powerful and competent ruler to direct and maintain its operations . While Alexios , John and Manuel ruled ( " c . " 1081 – " c . " 1180 ) , the Komnenian army provided the empire with a period of security that enabled Byzantine civilization to flourish . Yet , as we shall see , at the end of the twelfth century the competent leadership upon which the effectiveness of the Komnenian army depended largely disappeared . The consequences of this breakdown in command were to prove disastrous for the Byzantine Empire . Neglect under the Angeloi . In the year 1185 , the emperor Andronikos I Komnenos was killed . With him died the Komnenos dynasty , which had provided a series of militarily competent emperors for over a century . They were replaced by the Angeloi , who have the reputation of being the most unsuccessful dynasty ever to occupy the Byzantine throne . The army of the Byzantine empire at this point was highly centralised . It was dominated by a system in which the emperor gathered together his forces and personally led them against hostile armies and strongholds . Generals were closely controlled , and all arms of the state looked to Constantinople for instruction and reward . However , the inaction and ineptitude of the Angeloi quickly lead to a collapse in Byzantine military power , both at sea and on land . Surrounded by a crowd of slaves , mistresses and flatterers , they permitted the empire to be administered by unworthy favourites , while they squandered the money wrung from the provinces on costly buildings and expensive gifts to the churches of the metropolis . They scatterred money so lavishly as to empty the treasury , and allowed such licence to the officers of the army as to leave the Empire practically defenceless . Together , they consummated the financial ruin of the state . The empire ' s enemies lost no time in taking advantage of this new situation . In the east the Turks invaded the empire , gradually eroding Byzantine control in Asia Minor . Meanwhile in the west , the Serbs and Hungarians broke away from the empire for good , and in Bulgaria the oppressiveness of Angeloi taxation resulted in the Vlach - Bulgarian Rebellion late in 1185 . The rebellion led to the establishment of the Second Bulgarian Empire on territory which had been vital to the empire ' s security in the Balkans . Kaloyan of Bulgaria annexed several important cities , while the Angeloi squandered the public treasure on palaces and gardens and attempted to deal with the crisis through diplomatic means . Byzantine authority was severely weakened , and the growing power vacuum at the centre of the empire encouraged fragmentation , as the provinces began to look to local strongmen rather than the government in Constantinople for protection . This further reduced the resources available to the empire and its military system , as large regions passed outside central control . Analysis of the Byzantine military collapse . Structural weaknesses . It was in this situation that the disintegration of the military ' theme ' system , which had been the foundation of the empire ' s remarkable success from the eighth to eleventh centuries , revealed itself as a real catastrophe for the Byzantine state . The first advantage of the theme system had been its numerical strength . It is thought that the Byzantine field army under Manuel I Komnenos ( r . 1143 – 1180 ) had numbered some 40 , 000 men . However , there is evidence that the thematic armies of earlier centuries had provided the empire with a numerically superior force . The army of the theme of Thrakesion alone had provided about 9 , 600 men in the period 902 – 936 , for example . Furthermore , the thematic armies had been stationed in the provinces , and their greater independence from central command meant that they were able to deal with threats quickly at a local level . This , combined with their greater numbers , allowed them to provide greater defense in depth . The other key advantage of the theme system was that it had offered the Byzantine state good value for money . It provided a means of cheaply mobilising large numbers of men . The demise of the system meant that armies became more expensive in the long run , which reduced the numbers of troops that the emperors could afford to employ . The considerable wealth and diplomatic skill of the Komnenian emperors , their constant attention to military matters , and their frequent energetic campaigning , had largely countered this change . But the luck of the empire in having the talented Komneni to provide capable leadership was not a long - term solution to a structural problem in the Byzantine state itself . After the death of Manuel I Komnenos in 1180 , the Angeloi had not lavished the same care on the military as the Komneni had done , and the result was that these structural weakness began to manifest themselves in military decline . From 1185 on , Byzantine emperors found it increasingly difficult to muster and pay for sufficient military forces , while their incompetence exposed the limitations of the entire Byzantine military system , dependent as it was on competent personal direction from the emperor . The culmination of the empire ' s military disintegration under the Angeloi was reached on 13 April 1204 , when the armies of the Fourth Crusade sacked Constantinople . Conclusion . Thus , the problem was not so much that the Komnenian army was any less effective in battle ( the thematic army ' s success rate was just as varied as that of its Komnenian counterpart ) ; it is more the case that , because it was a smaller , more centralised force , the twelfth century army required a greater degree of competent direction from the emperor in order to be effective . Although formidable under an energetic leader , the Komnenian army did not work so well under incompetent or uninterested emperors . The greater independence and resilience of the thematic army had provided the early empire with a structural advantage that was now lost . For all of the reasons above , it is possible to argue that the demise of the theme system was a great loss to the Byzantine empire . Although it took centuries to become fully apparent , one of the main institutional strengths of the Byzantine state was now gone . Thus it was not the army itself that was to blame for the decline of the empire , but rather the system that supported it . Without strong underlying institutions that could endure beyond the reign of each emperor , the state was extremely vulnerable in times of crisis . Byzantium had come to rely too much on individual emperors , and its continued survival was now no longer certain . While the theme system ' s demise did play a major role in the empire ' s military decline , other factors were important as well . These include : Armies of the successor states and of the Palaeologi . After 1204 the emperors of Nicaea continued some aspects of the system established by the Komneni . However , despite the restoration of the empire in 1261 , the Byzantines never again possessed the same levels of wealth , territory and manpower that had been available to the Komnenian emperors and their predecessors . As a result , the military was constantly short of funds . After the death of Michael VIII Palaiologos in 1282 , unreliable mercenaries such as the grand Catalan Company came to form an ever larger proportion of the remaining forces . At the fall of Constantinople in 1453 , the Byzantine army totaled about 7 , 000 men , 2 , 000 of whom were foreign mercenaries . Against the 80 , 000 Ottoman troops besieging the city , the odds were hopeless . The Byzantines resisted the third attack by the Sultan ' s elite Janissaries and according to some accounts on both sides were on the brink of repelling them , but a Genoan general in charge of a section of the defense , Giovanni Giustiniani , was grievously wounded during the attack , and his evacuation from the ramparts caused a panic in the ranks of the defenders . Many of the Italians , who were paid by Giustiniani himself , fled the battle . Some historians suggest that the Kerkoporta gate in the Blachernae section had been left unlocked , and the Ottomans soon discovered this mistake – although accounts indicate that this gain for the Ottomans was in fact contained by defenders and pushed back . The Ottomans rushed in . Emperor Constantine XI himself led the last defense of the city by himself . Throwing aside his purple regalia , he stood in front of the oncoming Ottoman Turks with sword and shield in hand . The emperor was struck twice by the Turk troops , the mortal blow being a knife to his back . There , on the walls of Constantinople , alone and abandoned by his remaining troops , the emperor died . The fall of the Byzantine capital meant the end of the Roman empire . The Byzantine army , the last surviving direct descendant of the Roman legion s , was finished . Manpower . The exact size and composition of the Byzantine army and its units is a matter of considerable debate , due to the scantness and ambiguous nature of the primary sources . The following table contains approximate estimates . All estimates excludes the number of oarsmen , for those estimates see Byzantine navy . According to Mark Whittow the military resources of the Byzantine Empire were broadly comparable to those of other early medieval European states . As such Byzantium may not have been wealthier or more powerful than other European states , but it was more centralized and more united , and this was a vital factory in its survival . By using various Byzantine sources he guesses the entire cavalry forces of the empire , between the 8th and 10th centuries , were somewhere just over 10 , 000 and the number of infantry 20 , 000 , and argues that the Byzantine armies should be numbered in hundreds or thousands and not tens of thousands . Byzantine troop types . Cataphracts . The word cataphract ( from the Greek κατάφρακτος , " kataphraktos " , with a literal meaning of ' completely armored ' in English ) was what Greek - and later Latin - speaking peoples used to describe heavy cavalry . Historically , the cataphract was a heavily armed and armoured cavalryman who saw action from the earliest days of Antiquity up through the High Middle Ages . Originally , the term cataphract referred to a type of armour worn to cover the whole body and that of the horse . Eventually the term described the cavalryman himself . The cataphracts were both fearsome and disciplined . Both man and horse were heavily armoured , the riders equipped with lances , bows and maces . These troops were slow compared to other cavalry , but their effect on the battlefield , particularly under the Emperor Nikephoros II , was devastating . More heavily armoured types of cataphract were called " clibanarii " ( " klibanaphoroi " ) . These were eventually subsumed by the cataphract , and as such most Byzantine heavy cavalry became known as cataphracts . Cavalry . The Byzantine cavalry were ideally suited to combat on the plains of Anatolia and northern Syria , which , from the seventh century onwards , constituted the principal battleground in the struggle against the forces of Islam . They were heavily armed using lance , mace and sword as well as strong composite bows which allowed them to achieve success against lighter , faster enemies , being particularly effective against both the Arabs and Turks in the east , and the Hungarians and Pechenegs in the west . By the mid - Byzantine period ( c900 - 1200 ) the regular mounted arm was broadly divided into " katafraktoi " ( heavily armored and intended for shock action ) , " koursorses " ( medium weight equipped with mail or scale armor ) and lightly armed horse archers . Infantry . The Byzantine Empire ' s military tradition originated in the late Roman period , and its armies always included professional infantry soldiers . Though they varied in relative importance during the Byzantine army ' s history , under Basil II in particular heavy infantry were an important component of the Byzantine army . These troops generally had mail armour , large shields , and were armed with swords and spears . Under militarily competent emperors such as Basil II , they were among the best heavy infantry in the world . Pronoiars . Pronoiar troops began to appear during the twelfth century , particularly during the reign of the emperor Manuel I Komnenos ( 1143 – 1180 ) . These were soldiers paid in land instead of money , but they did not operate under the old theme system of the middle Byzantine period . Pronoiai developed into essentially a license to tax the citizens who lived within the boundaries of the grant ( the paroikoi ) . Pronoiars ( those who had been granted a pronoia ) became something like tax collectors , who were allowed to keep some of the revenue they collected . These men are therefore generally considered to have been the Byzantine equivalent of western knights : part soldiers , part local rulers . However , it is important to note that the emperor was still the legal owner of the Pronoiars ' land . Usually cavalry , pronoiars would have been equipped with mail armour , lances , and horse barding . Manuel re - equipped his heavy cavalry in western style at some point during his reign ; it is likely that many of these troops would have been pronoiars . These troops became particularly common after 1204 , in the service of the Empire of Nicaea in western Asia Minor . Akritoi . " Akrites " ( plural " Akritoi " or " Akritai " ) were defenders of the Anatolian borders of the Empire . They appeared after either the Arab conquests , or much later when Turkish tribes raided Anatolia from the east . The Akritoi units were formed from native Greeks living near the eastern borders . Whether such men were really soldier - farmers or lived on rents from smallholdings while concentrating on their military duties is still a matter of debate . The Akritoi were probably mostly light troops , armed with bows and javelins . They were most adept at defensive warfare , often against raiding Turkish light horsemen in the Anatolian mountains , but could also cover the advance of the regular Byzantine army . Their tactics probably consisted of skirmishing and ambushes in order to catch the fast - moving Turkish horse - archers . Greek folklore and traditional songs of the Byzantine era to the 19th century heavily feature Akrites and their ( always exaggerated ) deeds ( see acritic songs ) . Foreign and mercenary soldiers . The Byzantine army frequently employed foreign mercenary troops from many different regions . These troops often supplemented or assisted the empire ' s regular forces ; at times , they even formed the bulk of the Byzantine army . But for most of the Byzantine army ' s long history , foreign and military soldiers reflected the wealth and might of the Byzantine empire , for the emperor who was able to gather together armies from all corners of the known world was formidable . Foreign troops during the late Roman period were known as the " foederati " ( " allies " ) in Latin , and during the Byzantine period were known as the " Phoideratoi " ( Gr . Φοιδεράτοι ) in Greek . From this point , foreign troops ( mainly mercenaries ) were known as the Hetairoi ( Gr . Ἑταιρείαι , " Companionships " ) and most frequently employed in the Imperial Guard . This force was in turn divided into the Great Companionships ( Μεγάλη Εταιρεία ) , the Middle Companionships ( Μέση Εταιρεία ) , and the Minor Companionships ( Μικρά Εταιρεία ) , commanded by their respective " Hetaireiarches " – " Companionship lords " . These may have been divided upon a religious basis separating the Christian subjects , Christian foreigners , and non - Christians , respectively . Barbarian tribes . During the beginning of the 6th century , several barbarian tribes who eventually destroyed the Western Roman Empire in the 5th century eventually were recruited in the armies of the Eastern Roman Empire . Among them were the Heruli , who had deposed the last Western Roman Emperor Romulus Augustulus under their leader Odoacer in 476 . Other barbarians included the Huns , who had invaded the divided Roman Empire during the second quarter of the 5th century under Attila , and the Gepids , who had settled in the Romanian territories north of the Danube River . It was these same barbarian mercenaries that Emperor Justinian had used to help his legions reclaim the lost Roman territories of the West , which including Italy , North Africa , Sicily , and Gaul . The Byzantine general Belisarius used Hunnic archers and Heruli mercenaries in his army to reclaim North Africa and the Balearic Islands from the Vandals , and in 535 - 537 , he recruited Heruli infantry and Hunnic horsemen to help him secure Sicily and all of southern Italy , as well as defend the city of Rome from the Ostrogoths . In 552 , the Armenian general Narses defeated the Ostrogoths with an army that contained a large number of Germanic soldiers , including 3 , 000 Heruli and 400 Gepids . Two years later , Narses crushed a combined army of invading Franks and Alemanni with a Roman army that including a contingent of Heruli mercenary troops . Additionally , during the Komnenian period , the mercenary units would simply be divided by ethnicity and called after their native lands : the Inglinoi ( Englishmen ) , the Phragkoi ( Franks ) , the Skythikoi ( Scythians ) , the Latinikoi ( Latins ) , and so on . Ethiopians even served during the reign of Theophilos . These mercenary units , especially the Skythikoi , were also often used as a police force in Constantinople . Varangian guard . The most famous of all Byzantine regiments was the legendary Varangian Guard . This unit traced its roots to the 6 , 000 Rus sent to Emperor Basil II by Vladimir of Kiev in 988 . The tremendous fighting abilities of these axe - wielding , barbarian Northerners and their intense loyalty ( bought with much gold ) established them as an elite body , which soon rose to become the Emperors ' personal bodyguard . This is further exemplified by the title of their commander , " Akolouthos " ( Ακόλουθος , " Acolyte / follower " to the Emperor ) . Initially the Varangians were mostly of Scandinavian origin , but later the guard came to include many Anglo - Saxons ( after the Norman Conquest ) as well . The Varangian Guard fought at the Battle of Beroia in 1122 with great distinction , and were present at the Battle of Sirmium in 1167 , in which the Byzantine army smashed the forces of the Kingdom of Hungary . The Varangian Guard is thought to have been disbanded after the sack of Constantinople by the forces of the Fourth Crusade in 1204 ; nearly all contemporary accounts agreed that they were the most important Byzantine unit present and were instrumental in driving off the first Crusader assaults . Byzantine weapons . The Byzantines originally used weapons developed from their Roman origins , swords , spears , javelins , slings and bows etc . However they were gradually influenced by the weapons of their Turkish and Arab neighbors , adopting the use of the composite bow and the cavalry mace There were many sword ( " xiphos " ) types ; straight , curved , one - and two - handed , which are depicted in illustrations . According to the " Strategika " , by the sixth century the short Roman " gladius " had been abandoned in favor of a long two - edged sword , the spathion , used by both the infantry and cavalry . The tenth century " Sylloge tacticorum " gives the length of this kind of sword as the equivalent of 94 cm and mentions a new saber - like sword of the same length , the " paramerion " , a curved one - edged slashing weapon for cavalrymen . Both weapons could be carried from a belt or by a shoulder strap . Infantrymen and cavalrymen carried spear s for thrusting and javelins for throwing . Cavalrymen of the sixth and seventh century wielded lances with a thong in the middle of the shaft ( Avar style ) and a pennant . Infantrymen ' s spears ( " kontaria " ) in the tenth century were 4 - 4 . 5 meters long ( cavalry lances were slightly shorter ) with an iron point ( " xipharion " , " aichme " ) . One type of spear , the " menaulion " , is described in detail ; it was very thick , taken whole from young oak or cornel saplings and capped by a long blade ( 45 – 50 cm ) , for use by especially strong infantrymen ( called " menaulatoi " after their weapon ) against enemy " kataphraktoi " - an excellent example of a weapon and a type of specialized soldier developed for a specific tactical role . Both light infantry and cavalry carried javelins ( akontia , riptaria ) no longer than three meters . Maces ( " rabdia " ) and axes ( " pelekia " , " tzikouria " ) served as shock weapons . The tenth century " kataphraktoi " carried heavy all - iron maces ( " siderorabdia " ) – six - , four - or three - cornered – to smash their way through enemy infantry . Infantrymen used maces and battle - axes in hand - to - hand combat ; the two handed axe was the preferred weapon of the mercenaries from Rus ' and Varangian Guard of the tenth and eleventh centuries . Byzantine axes were single - bladed ( rounded or straight edged ) , sometimes with a spike opposite the blade . The sling ( " sphendone " ) and the bow ( " toxon " ) were the weapons used by light soldiers . Slings were the ordinary hand - held type ; the Roman staff sling ( " fustibalis " ) was apparently little used . The Byzantine bow , like the late Roman bow , was the composite , reflex type featuring an unbendable horn grip with the reinforced wooden bowstave slung in reverse of the bow ' s natural flex when unstrung . A bowshot ( flight , not target , range ) is over three hundred meters for an infantry bow , but cavalry bows , standing 1 . 2 meters high , were smaller and less tightly strung for greater accuracy and ease of handling , they had a flight range of 130 – 135 meters . The " solenarion " is a hollow tube through which an archer could launch several small arrows ( " mues " , i . e . , " mice " ) at a time ; Anna Komnene remarked that the Crusader ' s Western - type crossbow , which she called a " tzangra " , was unknown to Byzantium before the 12th century . Evidence for Weapons . Representational evidence , including propaganda monuments , gravestones , tombs , and the Exodus fresco , often shows Roman soldiers with one or two spears ; one tombstone shows a soldier with five shorter javelins . Archaeological evidence , from Roman burials and Scandinavian bog - deposits , shows similar spearheads , though the shafts are rarely preserved . Representational evidence sometimes still shows Roman swords . Archaeological evidence shows that the gladius has disappeared ; various short " semispathae " supplement the older " pugiones " while medium - long " spathae " replace the medium - short " gladii " . These have the same straight double - edged blades as older Roman swords . Representational evidence and recovered laths , as well as arrowheads and bracers , show Roman use of composite bows . Evidence for Shields . Representational evidence , recovered bosses , and some complete shields from Dara , show that most Roman infantry and some Roman cavalry carried shields . Evidence for Armor . Although the representational evidence , including gravestones and tombs , often shows soldiers without armor , the archaeological evidence includes remains of lamellar , mail , and helmets . Byzantine military philosophy . It is worth noting that the Empire never developed or understood the concept of a " holy war " . Its neighbours ' concepts of Jihad and Crusade seemed to it gross perversions of scripture or simple excuses for looting and destruction . Emperors , generals and military theorists alike found war to be a failing of governance and political relations , to be avoided whenever possible . Only wars waged defensively or to avenge a wrong could in any sense be considered just , and in such cases the Byzantines felt that God would protect them .