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 cataphractarii 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, cohorts and cavalry alae survived there, and newer units were created (the new legions, or auxilia and vexillationes, 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.


 * 1) The guard troops stationed in the capital.
 * 2) The comitatenses of the old Roman field armies. In Justinian's day these were more commonly called stratiotai. Regular soldiers of the Roman army, the stratiotai were chiefly recruited from subjects of the empire in the highlands of Thrace, Illyricum and Isauria.
 * 3) The limitanei. The least changed element of the Roman army, limitanei still performed their traditional duties of guarding frontiers and garrisoning border posts.
 * 4) The foederati. They were a relatively new element in the army, recruited from the fifth century onwards from barbarian volunteers. They were formed into cavalry units under Roman officers. A ban on enlistments by Roman subjects was lifted in the sixth century, and their composition became mixed.
 * 5) The Allies. These were bands of barbarians, Huns, Herules, Goths or others who were bound by treaty to provide the empire with military units commanded by their own chiefs, in return for land or yearly subsidy.
 * 6) The bucellarii. The private armed retainers of generals, Praetorian Prefects, officers of lesser rank and the rich, the bucellarii were often a significant portion of a field army's cavalry force. The size of a retinue of bucellarii depended on the wealth of the employer. Their rank and file were called hypaspistai, or shield-bearers, and their officers, doryphoroi or spear-bearers. Doryphoroi took solemn oaths of fidelity to their patron and of loyalty to the emperor. One of most noted generals of the period, Belisarius, had been a doryphoros in Justinian's retinue before his becoming emperor. The bucellarii were usually mounted troops, mostly Huns, Goths and mountaineers of Thrace or Asia Minor.

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 Themata
The themata (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:
 * the Armeniac Theme (Θέμα Άρμενιάκων, Thema Armeniakōn), first mentioned in 667, was the successor of the Army of Armenia. It occupied the old areas of the Pontus, Armenia Minor and northern Cappadocia, with its capital at Amasea
 * the Anatolic Theme (Θέμα Άνατολικῶν, Thema Anatolikōn), first mentioned in 669, was the successor of the Army of the East (Άνατολῆ). It covered central Asia Minor, and its capital was Amorium.
 * the Opsician Theme (Θέμα Ὀψικίου, Thema Opsikiou), first mentioned in 680, was where the imperial retinue (in Latin Obsequium), was established. It covered northwestern Asia Minor (Bithynia, Paphlagonia and parts of Galatia), and was based at Nicaea. Its commander bore the title of komēs ("count")
 * the Thracesian Theme (Θέμα Θρακησίων, Thema Thrakēsiōn), first mentioned in 680, was the successor of the Army of Thrace. It covered the central western coast of Asia Minor (Ionia, Lydia and Caria), with capital at Ephesos.
 * the corps of the Carabisiani (Kαραβησιάνοι, Karabēsianoi), first mentioned in 680, probably formed from the remnants of the Army of the Illyricum or the old quaestura exercitus. It occupied the southern coast of Asia Minor and the Aegean Islands, with its capital at Attaleia. It was a naval corps (κάραβις means "ship"), and its commander bore the title of droungarios. It was replaced with the Cibyrrhaeot Theme in the early 8th century.

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 tourmai. 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 tourmai. 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:
 * the Scholai (Gr. Σχολαί, "the Schools"), the most senior unit, the direct successor of the imperial guards established by Constantine the Great.
 * the Exkoubitoi or Exkoubitores (Lat. Excubiti, Gr. Ἐξκούβιτοι, "the Sentinels"), established by Leo I.
 * the Arithmos (Gr. Ἀριθμός, "Number") or Vigla (Gr. Βίγλα, from the Latin word for "Watch"), promoted from thematic troops by the Empress Eirene in the 780s, but of far older ancestry, as the archaic names of its ranks indicate. By the reign of Nicephorus I (802-11) the Vigla had become a permanent part of the tagmata with responsibility for guarding the Sacred Palace and the Hippodrome in Constantinople. The regiment performed special duties on campaign, including guarding the imperial camp, relaying the Emperor's orders, and guarding prisoners of war.
 * the Hikanatoi (Gr. Ἱκανάτοι, "the Able Ones"), established by Emperor Nicephorus I in 810.

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. Ὀπτιμάτοι, "the Best"), a support unit responsible for the mules of the army's baggage train (the τοῦλδον, touldon).

There was also the Hetaireia (Gr. Ἑταιρεία, "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.

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.

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:


 * An increasing reliance on foreign mercenaries, which also contributed to the Byzantine Navy's decline.
 * A long, slow decay in the quality and prestige of the ordinary, non-elite Byzantine infantry.
 * A creeping Feudalism that helped to erode centralized administration.
 * Increasing emulation of Western (or Latin) weapons, equipment and warfare methods, beginning especially during the reign of Manuel I Komnenos.

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 legions, 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.

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 spears 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.

Early Byzantine period

 * Battle of Callinicum (531)
 * Battle of Tricamarum (533)
 * Battle of Taginae (552)
 * Battle of Nineveh (627)
 * Battle of Mu'tah (629)
 * Battle of Firaz (634)
 * Battle of Ajnadayn (634)
 * Battle of Fahl (635)
 * Battle of Yarmouk (636)
 * Battle of Iron Bridge (637)
 * Battle of Ongala (680)
 * Battle of Carthage (698)
 * Siege of Constantinople (718)

Middle Byzantine period

 * Battle of Pliska (811)
 * Battle of Bulgarophygon (896)
 * Battle of Acheloos (917)
 * Battle of Kleidion (1014)
 * Battle of Manzikert (1071)
 * Battle of Dyrrhachium (1081)
 * Battle of Levounion (1091)
 * Siege of Nicaea (1097)
 * Battle of Beroia (1122)
 * Battle of Sirmium (1167)
 * Battle of Myriokephalon (1176)

Late Byzantine period

 * Battle of Antioch on the Meander (1211)


 * Battle of Pelagonia (1259)
 * Fall of Constantinople (1453)