Focus on Military Organization: Early Medieval Byzantine Army Structures (c. 500-c.1000 CE)
The high point of Byzantine power and territorial expansion took place in the sixth century during the reign of Emperor Justinian (r.527-565 CE), often referred to as “the Great.” Described by his chroniclers as “the emperor who never sleeps,” Justinian was a vigorous, intelligent and ambitious ruler who was determined to reestablish the Roman Empire throughout the Mediterranean basin, ordering Byzantine armies to fend off Sassanian Persian attacks on the eastern frontiers of Anatolia and the Levant while also regaining parts of Italy from the Ostrogoths and North Africa from the Vandals. In 527, Justinian inherited an empire policed by five mobile field armies and a large number of smaller regional armies (limitanai) located along and behind the frontiers. These five field armies (comitatenses) were the Army of the East (a large region that included Egypt and the Levantine, Armenian, and Mesopotamian frontiers), the Army of Thrace, the Army of Illyricum, and two local imperial guard armies located in Thrace and northwestern Anatolia to protect Constantinople. Each field army was commanded by a “Master of the Soldiers” (magister militum). Justinian added two new field armies during his reign to police his new acquisitions (the Armies of Africa and Italy) and split a third off from the Army of the East to create the Army of Armenia, reflecting the increased strategic importance of this region to Byzantium, an importance that intensified from this period to the battle of Manzikert in 1071. By the end of his reign in 565 there were over twenty-five regional commands serving as both military and police forces throughout the empire.
RIGHT: Close-up of a Byzantine heavy cavalryman cataphract lancing a Goth or Lombard, from the Isola Rizza Dish. Late Sixth Century CE. Castelvecchio Museum. Verona, Italy.
The constitution of Justinian’s Byzantine armies differed from those of their Roman predecessors in that cavalry, rather than infantry, was the dominant tactical arm. This switch in emphasis took place due to prolonged martial contacts with horse cultures from the Eurasian Steppes or the influence of these cultures on Near Eastern empires. The most formidable threat came from the Sassanian Persians who fought like their Parthian forerunners using predominately light cavalry archers and heavy cavalry lancers who sometimes carried bows. Introduced into the Roman art of war by the Emperor Hadrian (r.117-138) and widely used in the East in the last years of the Roman Empire, Roman cataphractii and clibanarii (terms often used interchangeably by classical authors) mimicked their Parthian and later Sassanian heavy cavalry foes in both equipment and tactics, functioning as heavily armored lancers or as mounted archers. By the fifth century, the proportional relationship between cavalry and infantry units was 1:3 (meaning one out of three units in the Byzantine army were cavalry units, although the total number of horsemen in the army continued to be dwarfed by infantry due to the larger size of infantry units) and fifteen percent of all cavalry units consisted of heavy cavalry cataphractii, now called kataphraktoi by Byzantine authors. The overall percentage of cavalry in the Byzantine army continued to rise through the reign of Justinian and into the seventh century and would be a decisive tactical arm in his wars against the Sassanians. Byzantine heavy cavalry kataphraktoi supplemented standard cavalry formations, deployed to reinforce the Byzantine battle line while acting as a counterbalance to similar units deployed by the Persians.
Byzantine military doctrine during the age of Justinian emphasized combined-arms warfare using cavalry and infantry. Much of our knowledge of Byzantine military organization and tactics comes from an anonymous Byzantine author writing sometime in the sixth century. This author, who was probably a military engineer, stated that Byzantine infantry were drawn up in square or oblong formations, with the first four ranks in the front and flanks armed with thrusting spears, while those in rear ranks were armed with javelins. Long straight swords were a common side-arm. The anonymous author goes on to write that front rank infantry were equipped with large round shields one-and a half yards in diameter “so that when they joined together they form a solid, defensive protection behind which the army can hide without anyone being injured by enemy missiles.” He continues on remarking that these shields “should have an iron circlet embossed in the center of the shield in which a spike at least four fingers long should be fixed, both to unnerve the enemy when they see it from a distance and to inflict serious injury when used at close range.” Byzantine soldiers were also protected by helmets, chainmail or lamellar armor. Light infantry wore very little body armor and carried a composite bow with a quiver of forty arrows, a small shield, and an axe for close combat, while those not equipped with bows used javelins.
LEFT: A living history reenactor wearing a Byzantine infantry panoply, c.1000 CE. Notice the lamellar armor over the padded gambeson (kavadion), and the conical helm in hand. Grasped is his infantry spear (menaulion) while at his side in scabbard is a replica sword (paramerion) as a secondary weapon. Even the high hose and soft shoes are period accurate, although leather wrapping may have been worn in lieu of greaves for poorer soldiers.
By the early sixth century, a Byzantine army’s regimental organization varied widely, made up generally of three kinds of troops: numeri, foederati and bucellarii. The numeri were regular imperial soldiers conscripted from Byzantine territory, while the foederati grew out of regiments of foreign allied soldiers who settled in the Roman Empire in the late fourth century and retained their own military organization and command. By the sixth century, foederati units could be made up of soldiers from ethnically diverse regions, much like a modern foreign legion, or of a homogenous ethnic group with special tactical capabilities. Huns, Armenians, Persians, Arabs and Slavs served in these units, as did Germanic troops, depending on the theater of operations. Each “Master of the Soldiers” also had a private guard known as bucellarii, paid for out of his own purse. These units could be quite large (general Belisarius’ bucellarii guard regularly numbered over 1,000 men). By the late sixth century, these units were assimilated into the imperial army as special divisions of elite soldiers. In battle, Byzantine military doctrine followed a classical model, usually placing light infantry in the front to screen the army while the heavy infantry generally formed up in the center either in front of the cavalry, or as a second line behind the cavalry, relying on the Byzantine horse to break up the enemy formation before following up. Cavalry could also be placed on the wings, usually across from enemy cavalry formations with the intent of driving off the enemy horse and attacking the vulnerable flanks of the center infantry formations. Most Byzantine generals used their personal bucellarii guard as a tactical reserve.
THE BYZANTINE ARMY IN TRANSISTION IN THE WAKE OF THE ISLAMIC CONQUESTS
The expansion of Islam in the seventh century fundamentally changed the political and strategic landscape of the Mediterranean basin. Muslim armies swept north into Palestine and Syria and Mesopotamia, defeating the Sassanians at Qadisiya in 636 and destroying their Persian Empire by 651. Arab armies then pushed west across North Africa to the Atlantic Ocean, swallowing up Byzantine possessions in Egypt, Libya and Tunisia along the way. By 700 all of North Africa was under Islamic control. In the Levant, the devastating Byzantine loss at Yarmuk in 636 forced the Eastern Romans to pull their field armies from Palestine first to Northern Syria and Mesopotamia, and then to the natural Anatolian frontier line consisting of the Taurus and Anti-Taurus mountain ranges in southeastern and eastern Turkey. Further east, the Byzantine capital of Constantinople weathered two determined Muslim sieges between the years 674-678 and again in 717-718, illustrating the vulnerability of the heart of the Eastern Roman Empire.
Byzantium’s territorial contraction required adjustments in its field army placements. Emperor Constans II (r.641-668) settled his remaining field armies in specific districts called themata or themes. The new organization of themes introduced regionalized army groups under the command of a strategos who replaced the “Master of the Soldiers” and served as both a senior general and governor. The Opsikion Theme was made up of the two former praesental armies and was pulled back to its original bases in northwest Anatolia and Thrace. The Anatolikon Theme was made up of the former Army of the East and protected south-central Turkey, while the Armeniakon and Thrakesian themes were made up of the Armies of Armenia and Thrace. The Anatolikon Theme protected south-central Turkey while the Armeniakon Theme defended the dangerous eastern and northern districts of Asia Minor. However, when determined Arab attacks forced the Byzantines to abandon the region of Cilicia (south-central Anatolia adjacent to Muslim controlled Syria) at the end of the seventh century, imperial strategy shifted from trying to control a clearly defined frontier through pitch battles and territorial rollback to a strategy known by the Easter Romans as “shadowing warfare” consisting of harassing the invaders and attacking their logistical lines. The net effect of this strategy was the creation of an economically unstable and lawless frontier region between Byzantine and Umayyad controlled territories.
The thematic system military provided both regional frontier troops and mobile field armies through the creation of a dedicated militia. These troops became the legal holders of the land itself, a development that came in the form of imperial land grants that were similar to the land grants during the early Roman Empire that settled legionaries in newly conquered regions. Although the Byzantine soldiers did not work the fields or run farms on a full time basis, their ownership (and that of their heirs) brought about a personal stake in the defense of their theme and provided the emperor with manpower for his campaigns. The thematic system had an added benefit of removing soldiers from the imperial payroll through the substitution of a land grant at a time when the contracting empire was running out of money to pay its soldiers.
RIGHT: Byzantine Empire at the Death of Emperor Basil II, c.1025 CE.
Because if its militia nature, the themes primary role was that of a defensive force, but Constantine V (r.741-775) would take an interest in regaining lost territory and to fulfill this aim, created an imperial guard consisting of elite cavalry and infantry units called tagmata (Greek for “the regiments”). Constantine originally used these troops as a reaction to a rebellious theme in northwest Anatolia, and then later for offensive campaigns against the Arabs and Bulgars. Tagmata soldiers were recruited, equipped and paid a salary directly by the state and were under the direct command of the emperor. These well-trained and well-disciplined professional soldiers provided the core units of an imperial expeditionary army when supplemented by less reliable but more numerous local thematic militia. The most important of these imperial regiments were the Scholai, the Exkoubitoi, the Artihmos and the Hikanatoi under the control of a commanding general or domesticus rather than a strategos. The domesticus of the Scholai Tagmata usually assumed supreme command of Byzantine expeditionary armies if the emperor was not present on campaign.
The Byzantine army used the same organization of units whether they were troops from the themes or from the tagmata. The size of units on the battlefield varied depending on tactical need and there is no scholarly consensus on the numerical makeup of Byzantine armies. What is known is that the smallest unit was a bandum normally consisting of about 300-400 soldiers, which was commanded by a tribune or count. Five to eight banda, roughly 1,500-3,200 men, formed a turma under the command of a turmarch. Each turmarch had his base in a fortress town and was responsible for the defense of his district and served as an important military and civic leader in his theme. Normally, two or three turmae, roughly 4,500-9,600 men, formed a thematic army commanded by a strategos, although this number could vary widely. When imperial tagmata were added to thematic troops, the resulting expeditionary army could consist of tens of thousands of troops.
The role of cavalry and infantry in Byzantine military doctrine also slowly changed from the time of the great Muslim victories in the mid-seventh century. At that time, both the Byzantine and Arab armies used large infantry contingents in their arts of war as illustrated by the role of infantry in the signature battles of this period. Cavalry, especially light cavalry, became the dominant arm because of its strategic mobility, especially important in defending the broad expanses of the Balkans and Anatolia, and utility when fighting mounted Bulgar and Muslim raiders. Byzantine cavalry, like cavalry in most periods of history, tended to be of noble birth and were better trained and equipped than their usually common-born infantry counterparts. From the eighth century on Byzantine thematic infantry was better suited for garrison roles and irregular combat in difficult terrain as they were often the most unreliable troops on the battlefield. These troops did not perform as well as the infantry of Justinian and Herakleios’ time due to a lack of discipline and poor equipment. Quality heavy infantry would not return to the Byzantine art of war until the tenth century.
BYZANTIUM RESURGENT: MILITARY REFORMS AND TENTH CENTURY TERRITORIAL EXPANSION
One of the primary reasons for the renewed success of Byzantine military operations in the tenth century was a rededication to sound military principles and organization and the adoption of new arms and armor. Several new military treatises were authored in the tenth century reflecting these changes centered on a revival of disciplined heavy infantry capable of fighting on their own against enemy infantry and cavalry or operating with their own heavy cavalry using combined-arms tactics. Leo VI’s reign initiated a renaissance in the study of military doctrine.
LEFT: Byzantine cavalry weilding Capture of Berroia (Aleppo) by the Byzantines under Nikephoros Phokas in 962 CE. From the History of John Skylitzes (Skyllitzes Matritensis (Biblioteca Nacional de España).
His Taktika preserved those elements of Maurice’s Strategikon that were still relevant and added new lessons learned in the ninth century from wars against the Bulgars and Islam. In the second half of the tenth century two other important treatise were written. The first, commonly known by its Latin title as Praecepta Militaria (A Composition on Warfare) was either written by or for Emperor Nikephoros II Phokas (r.963-969) and emphasizes the practical elements of infantry and cavalry warfare, encampment and use of spies. The second treatise also entitled Taktika is attributed to Nikephoros Ouranus and expands on earlier Byzantine manuals, but reveals the lessons learned during his generalship in the wars of Emperor Basil II in the late tenth and early eleventh centuries.
Four types of infantry served in Byzantine armies in the second half of the tenth century. The lightest of the four were the psilos, unarmored javelineers and slingers used as skirmishers and to screen the heavier infantry and cavalry in battle. The second type of infantry consisted of archers (although some sources lump bowmen into the psilos) wielding a powerful short composite bow adopted through contacts with steppe peoples. Some of these bows were modified into a powerful dart thrower called a solenarion that utilized a hand-held grooved channel or tube held up against the side of the composite bow. The dart’s length was between a normal arrow and the later crossbow bolt. This weapon is identical to the Islamic majra or nawak first seen in Muslim sources in the seventh century and used with great effect at the Arab victory at Qadisiya. A solenarion was an effective weapon because its dart was fired at such a high velocity that it could puncture any armor, had a long range, and was fired so quickly that the naked eye had a difficult time seeing it. Archers in support of heavier units wore light chainmail or lamellar armor, while others wore padded or no armor. A small round shield, twelve-inches in diameter, was also carried for defense. On campaign, each bowman was required to carry two bows, four bowstrings, two quivers (one with sixty arrows, the other with forty), a sling, a one-handed war axe (tzikourion), and a sword if available.
Infantry bowmen held a central place in Byzantine military doctrine as an effective counter to enemy mounted archery, whether it came from old enemies like the Arabs, Avars, Bulgars, Pechenegs and Magyars, or new ones like the emerging threat of the Seljuk Turks. However, in practice, Byzantine commanders did not have access to quality native bowmen. Military archery had been in decline since the eighth century, so much so that Leo VI proposed in his Taktika the reintroduction of mandatory archery practice and ordered his strategoi to ensure that every household possess a bow and forty arrows. Despite this initiative, native Byzantine archery remained a neglected military art.
A third kind of infantry called peltastoi also served in the Eastern Roman army, named after the heavy thick-necked javelin employed by these troops as either a missile or close-quarters weapon. Peltastoi were hybrid troops who acted as a bridge between light and heavy infantry and were used to either screen heavier footmen and cavalry or act as shock units when fighting alongside their heavier armed and armored brothers-in-arms. Peltastoi wore lamellar armor or chainmail when available and carried round shields. When armor was not available, a thick-quilted gambeson (kavadion) was worn instead made of thick cotton wadding in a raw silk cover.
The heaviest of these four infantry formations consisted of skutatoi, named after their large shield or skuta. Each skutatos wore a pull-on chainmail hauberk or scale armor and metal helmet, some of which were of the spangenhelm variety in favor in Western Europe and the Baltic region in the tenth century. The manuals of the period also suggested wearing limb armor to protect forearms (vambraces) and lower-legs (greaves). Their namesake shield was originally oval shaped, although this began to change as soldiers adopted a tear-drop shaped and then a kite-shaped shield reminiscent of the famous shields used by the Normans in the eleventh century. Skutatoi who served in the forward ranks used a thirteen-foot long pike or kontarion tipped with an eighteen-inch socketed spearhead. These front line troops wielded their pikes against enemy cavalry in both offensive and defensive action and could be deployed either in a line or in a wedge formation to break up enemy attacks. Skutatoi positioned in the rear ranks used shorter spears (menaulion). By the end of the tenth century specialized pike-wielding skutatoi made up ten percent of a 1,000 man regiment, integrated with 400 peltastoi and ordinary skutatoi, 300 archers and 200 psilos armed with javelins and slings. Both peltastoi and skutatoi carried one of two types of swords. The paramerion was a saber-hilted, slightly curved single-edged sword whose design was probably influenced by contacts with the steppe peoples, while the spathion was a straight double-edged long sword dating back to the late Roman Empire. Tzikourions were also used in conjunction with shields. Maces were not usually a part of the infantryman’s arsenal.
RIGHT: The paramerion was a saber-hilted, slightly curved single-edged sword whose design was probably influenced by contacts with the steppe peoples.
Byzantine commanders fielded four types of cavalry in the late tenth century. Light cavalry horse archers continued in their traditional role of pursuit and harassment of enemy forces and were an essential combat arm when facing similar mounted foes originating on the steppes. The kataphraktoi remained the premier heavy shock cavalry, although some of these heavy troops continued to employ short composite bows for missile combat. Under Nikephoros II some kataphraktoi were up-armored into a super-heavy cavalry called klibanophoroi reminiscent of Byzantine and Sassanian cataphractii seen during Justinian’s wars in the sixth century. Armor and barding was very heavy, with the rider covered in chain or lamellar armor with the additional protection of a padded overcoat. He wore an iron helmet with coif and chain mask that covered the entire face except for the eyes. Mounts were protected by an iron headpiece and chest barding made of ox-hide lamellar split at the front for ease of movement and leaving only the eyes, nostrils and lower legs unprotected from the front. Both heavy cavalries utilized a short lance or kontarion, although this weapon was about eight feet in length, much shorter than the skutatos’ infantry pike and shorter than the cavalry lances in favor later in Catholic Western Europe. The shortened length of the kontarion indicates lance work was not stressed; instead riders carried multiple edged and contusion weapons. The Praecepta Militaria suggested wearing two swords into combat, both the single-edged paramerion and the double-edged spathion suspended on waist belt and baldric. However, contemporary sources indicate the cavalry mace was the Byzantine heavy cavalrymen’s primary hand-to-hand weapon, with up to two spare maces carried holstered on the saddle.
The new tactical manuals reemphasized the role of the kataphraktos and klibanophoros at the point of attack, but the weight of the armor for both rider and horse meant these troops could only be used over short distances. In battle, these heavy horsemen drew up in a wedge formation, with twenty men in the first rank, twenty-four in the second and four more in each successive rank through the tenth and last rank, creating a formation of 384 heavy cavalry. Weight could be added to the attack by creating a larger wedge formation twelve ranks deep (504 horse). Light cavalry armed with bows were added to this formation at a ratio of about one horse archer per four lancers. Kataphraktoi and klibanophoroi would remain important to the Byzantine art of war until the debacle at Manzikert in 1071, after which these types of heavy cavalry became less important.
A fourth type of medium cavalry was also used by Byzantine commanders. Known as koursores, these mounted troops were expected to fill the role between light cavalry archers and heavy cavalry. Koursores engaged other medium or light cavalry or were used to run down detached or fleeing infantry. Riders wore chain or lamellar armor, carried a round shield thirty-two inches in diameter, and were armed with short kontarion (worn slung across the back when not in use), composite bow, one sword of either variety, and one or two maces. Koursores rode smaller faster horses capable of longer endurance and usually without barding. It should be noted that Byzantium’s access to the rich horse lands of Phrygia and Cappadocia in Anatolia helped secure quality cavalry mounts throughout the early medieval period. Byzantine expansion into Armenia in the tenth century increased that access and helped fuel the recovery. The permanent loss of most of Anatolia and its valuable horse lands to the Seljuk Turks after Manzikert ushered in a period of decline the Eastern Roman Empire never recovered from.
Byzantine cavalry, which had held the central role in Eastern Roman warfare since the rise of the tagmata in the eighth century, now had an equal partner on the battlefield with the return of well-equipped and well-disciplined infantry. In fact, the new Byzantine manuals emphasized combined-arms cooperation between infantry and cavalry reminiscent of the “mixed formations” mentioned in Maurice’s Strategikon. In battle, infantry and cavalry worked together in a new formation, essentially a hollow battle square or rectangular (depending on the terrain) where heavy and light infantry used pikes, spears and missile weapons to cope with encircling enemy cavalry while also providing a base for attacks and safe refuge for Byzantine cavalry units. Early medieval Byzantine military structures demonstrated a remarkable flexibility across centuries while maintaining the importance of combined-arms cooperation, cooperation capable of meeting a defeating a diverse range of enemies.
Suggested Readings:
Primary sources
Dennis, George T. The Taktika of Leo VI: Revised Edition. Dumbarton Oaks, 2014.
Dennis, George T. Maurice's Strategikon: Handbook of Byzantine Military Strategy. Dumbarton Oaks, 2001.
Dennis, George T. Three Byzantine Military Treatises. Dumbarton Oaks, 1985.
Sullivan, Dennis F. Siegecraft: Two Tenth-century Instructional Manuals. Dumbarton Oaks, 2000.
Secondary sources
Carey, Brian Todd, Joshua B. Allfree, and John Cairns. Road to Manzikert: Byzantine and Islamic Warfare, 527-1071. Pen and Sword Military, 2012.
Haldon, John. The Byzantine Wars. Stroud, Gloucestershire: The History Press, 2008.
Kaegi, Walter E. Byzantium and the Early Islamic Conquests. Cambridge University Press, 1992.
Luttwak, Edward N. The Grand Strategy of the Byzantine Empire. The Belknap Press of Harvard University Press, 2009.
Treadgold, Warren. Byzantium and Its Army, 284-1081. Stanford University Press, 1995.
Pen & Sword Military, 2021, By Brian Todd Carey.
From the publisher, "In August 1071, the Byzantine Emperor Romanus IV Diogenese led out a powerful army in an attempt to roll back Seljuk Turkish incursions into the Anatolian heartland of the Empire. Outmaneuvered by the Turkish sultan, Alp Arslan, Romanus was forced to give battle with only half his troops near Manzikert. By the end of that fateful day much of the Byzantine army was dead, the rest scattered in flight and the Emperor himself a captive. As a result, the Anatolian heart was torn out of the Empire and it was critically weakened, while Turkish power expanded rapidly, eventually leading to Byzantine appeals for help from Western Europe, thus prompting the First Crusade. This book sets the battle in the context of the military history of the Byzantine Empire and the Islamic World (Arab and Seljuk Turkish) up to the pivotal engagement at Manzikert in 1071, with special emphasis on the origins, course and outcome of this battle. The composition, weapons and tactics of the very different opposing armies are analyzed. The final chapter is dedicated to assessing the impact of Manzikert on the Byzantine Empire's strategic position in Anatolia and to the battle's role as a causus belli for the Crusades. Dozens of maps and battle diagrams support the clear text."
About the Author: Brian Todd Carey is an Assistant Professor of History and Military History at the American Public University System, where he teaches ancient, classical, medieval and early modern military history. He is the author of dozens of history articles in numerous magazines and journals, including Aviation History, Command Magazine, History Magazine, Marine Corps Gazette, Medieval History Magazine, Military Heritage, Military History, Strategy and Tactics, World History Bulletin, World at War, World War II, and WWII Quarterly: The Journal of the Second World War and seventeen articles on ancient, classical and medieval Eurasian warfare for the twenty-one volume ABC-CLIO-World History Encyclopedia. In 2007 he was the recipient of the American Public University System's Excellence in Teaching and Learning Award for the School of Arts and Humanities. He is the author of Warfare in the Ancient World, Warfare in the Medieval World, Hannibal's last Battle: Zama and the Fall of Carthage, and Road to Manzikert: Byzantine and Islamic Warfare, 527-1071. ☞ Buy a copy on Amazon
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