Heraclius’s recovery of Syria and Egypt from Persia in 626-628 was the last hurrah for the old Eastern Roman Empire. In addition to the provinces lost to the Arabs, Avars and Slavs wrested major areas of the Balkans and Thrace from imperial control. By 700, the empire had contracted to the capital and Asia Minor to the Taurus Mountains, plus small coastal territories in Greece and Italy: Half the population of the empire and perhaps two-thirds of its revenue were lost for good.
The grand strategy of the empire became strictly defensive—indeed, until the mid-eighth century, Byzantium fought for its very survival, repulsing sieges of Constantinople in the 670s and again in 717-718. The empire depended for its defense on its navy (see Chapter 10) and on a reorganized army. Losses of manpower and economic reserves and the limited opportunities for plunder imposed by a defensive posture meant that, while traditions of organization and of strategic and tactical thinking dating from Maurice’s Strategikon—a sixth-century military manual that was based on older Roman military handbooks—continued to inform Byzantine military policy, severely restricted resources forced significant change in the implementation of that policy.
Military change was part of a larger set of changes in the empire. The loss of great economic and cultural centers such as Antioch and Alexandria gave the capital at Constantinople dominance of Byzantine government, society, and culture. The patriarch of Constantinople gained in importance and prestige within the reduced world of eastern Christianity but became even more a part of the imperial system under the leadership of the emperor. Constantinople truly became “The City” in an empire whose cities generally were smaller and less important than they had been in the Roman period.
The prominence of Constantinople created an enduring characteristic of Byzantine life: a division between the center and the provinces that had a number of aspects and consequences. Economically, the provinces were overwhelmingly agrarian: Taxes on farmers, in cash and in kind, were the backbone of government revenues, the vast majority of which were used to support the army and navy. The capital was the center of the empire’s trade, where the government regulated and taxed merchants and craftsmen. Control of trade, with its ability to generate cash and its connections to the often hostile outside world, became part of the government’s defensive grand strategy. Socially, the provinces were increasingly the world of military aristocrats—men who were significant landholders and held positions of leadership in the provincial army. Such men were also important in the capital but were balanced and rivaled by the scholar-bureaucrats of the central government. A similar division existed between the government-dependent churchmen of the capital and the great landholding monasteries of the provinces, which were relatively independent.
Given the diminishing resources available for military use and the increasing importance of aristocratic landholders in society, Byzantium saw changes similar to those affecting western Europe in this period. But the restriction of resources was never as great, and so the rise of the aristocracy took place in the context of a central authority that retained its strength and dominance in this civilization. The wealth and security of the capital behind its walls contrasted with the poverty of the provinces and their continued openness to Arab invasions, at least through the 840s, reinforcing the fact that appointment to military command by the government, rather than independent dynasty building, remained the path to power and success in the empire. As the key to power, Constantinople held the remains of the empire together.
The conquests also affected the cultural tone of the empire. The Eastern Roman Empire had been Christian but had also retained significant elements of Roman secular culture. The loss of the great eastern Mediterranean centers of culture resulted in an empire whose culture was pervasively Christianized. The lost provinces had been religiously unorthodox, Monophysite, in their Christianity and Coptic or Syriac in language; their loss actually increased the homogeneity of the church, making it more Greek and more dependent on the leadership of the emperor. Finally, the pressures of defense, especially against a rival salvation religion, moved this Christianity toward greater militance and intolerance. This tendency had appeared even during Heraclius’s Persian wars: His campaign to retake Jerusalem in 628 and to regain the fragments of the True Cross taken from the city by the Persians is sometimes called the first “crusade.” And the tendency was magnified in the battle against Islam. Byzantine soldiers entered battle saying prayers to a conquering Jesus, and the central religious dispute in the empire, the Iconoclast controversy of the 700s (over the religious use of images) was influenced by the spiritual crisis prompted by Arab success and had implications for army morale and organization. The more sharply defined Greek Orthodox character of Byzantine Christianity affected not only warfare against the Arabs but Greek missionary work, which was tied more clearly to imperial authority than western missions were to any secular power. It also affected Byzantine relations with western Europe, which became increasingly strained as time went on.
Figure 8.3 The Byzantine Theme System The original four themes were subdivided over time, and the system was extended to European provinces and to newly conquered areas in Asia.
The century from 630 to 730 was the crucial one for most of these changes. It was also the critical period for the emergence of a new military posture, one which allowed Byzantium to survive and eventually prosper.
Evolution of the Theme System
Heraclius withdrew the four Roman field armies in the east—the armies of Armenia, the East (Anatolian), and Illyricum (Thrace), and the central reserve army (Obsequium)—into Asia Minor, eventually abandoning all the frontier areas beyond the Taurus Mountains and most of Thrace. Each field army (or theme, a word with origins in the steppe nomad world) was assigned part of Asia Minor as its home base, from which it was to draw support and recruits. In addition, a coastal area was later assigned to the rowers of a thematic navy. A fiscal crisis forced significant reductions in army pay, but in the impoverished empire, any cash salary was valuable, and recruits continued to be available, while taxes in kind provided various supplies.
The permanent basing of armies in regions of Asia Minor inevitably created an identification between the themes (armies) and their geographic areas (which also came to be called themes). This eventually had a major effect on provincial government. Roman government had maintained a clear division between civil and military authority. Increasingly, however, from the mideighth century, the strategos, the commander of the theme as a military unit, also became the military governor of the theme as a province. Civil authority thus was steadily subordinated to military officials. This streamlined provincial administration but had the potential to make the strategoi into powerful political figures who could threaten the emperor’s control. The shift to military administration in the eighth century, however, was accompanied by the subdivision of the original themes to reduce their political weight, while themes added when the empire again expanded tended to be small (Figure 8.3).
Byzantine Soldiers
This manuscript illustration of a Byzantine army in action shows the coordination of cavalry (foreground) with spear-armed infantry (background).
The shift to smaller themes was also accompanied by a subtle shift in strategic outlook. The thematic armies of the seventh century were still field armies that tried to meet invasions at the frontiers and, at least in theory, maintained offensive capability for reconquest of the empire’s lost provinces. But the realities—the dominance of the Caliphate as well as the creation of a central field army, the tagmata (see below)—pushed the themes toward being a more purely defensive militia.
The Thematic Armies in Operation Some of the thematic forces were infantrymen armed with spears or bows. Defensive armor among the foot soldiers was often minimal—padded tunics, felt caps, and an oval wooden shield—as mail or other metal body armor seems to have been beyond the resources of most infantry. The cavalry were more likely to have iron helmets and some body armor, though not all did; cavalry weapons included lances, swords, maces, and bows. Though probably numerically inferior to the infantry, the cavalry were clearly the more prestigious and better- supported force, drawn from prosperous middle-level landowners. As in western Europe, cavalry’s advantage over infantry was thus as much a matter of social factors as tactical ones, factors that tended to influence levels of armament and morale in the cavalry’s favor as well. A support system in which soldiers provided their own arms exaggerated the disparity.
Thus, Byzantine infantry suffered some of the same decline, compared to the legions of the classical empire, that infantry in western Europe did, for the same reasons. Above all, the Byzantine thematic forces were not full-time professionals and did not drill regularly (if at all) in peacetime—only regular campaigning provided some experience and cohesion. Moreover, the influence of nomadic horse armies on tactics and army composition was stronger than in western Europe, because Byzantine frontiers were so much closer to the grasslands of the nomadic invaders, and the climate was generally more suitable for horsed armies than that of western Europe. Also, the normal patterns of campaigning by thematic forces put a premium on the mobility that cavalry forces provided.
Nonetheless, the Byzantine system was built on carefully coordinated cooperation between infantry and cavalry forces, each of which had their roles to play. Solid masses of spear- and bow-armed infantry provided a secure defensive base for the cavalry during battles, defended and besieged fortifications, and defended tenaciously in restricted terrain such as mountain passes. A well-guarded pass could either block an enemy invasion or, more often, block the return of a raiding army to its home bases and allow other forces time to harass the raiders. In turn, the cavalry provided security and scouting for infantry columns on the march and could forage farther afield for supplies on campaign.
The defensive function of the thematic forces was dictated by the disparity in resources between the empire and its chief enemy, the Caliphate. The population of the Caliphate was many times larger than Byzantium’s 10 million or so, and the Arab economy was more advanced. The result was that the Caliphate’s cash income was perhaps twenty times that of the empire at the time of greatest disparity and probably seven times greater even in the mid-ninth century. The numbers of the Byzantine military establishment are much disputed because the sources are so scanty and unreliable, but it is likely that the entire Byzantine army at its height totaled little more than 40,000 soldiers—and probably less. But even if it were much larger, as some authors argue, only a fraction of the total could campaign at any one time: Byzantine armies in the seventh century never exceeded 20,000 and only rarely reached 40,000 in the eighth, while the largest Arab armies could regularly exceed 40,000. A significant thematic force could be as small as 3000 men.
In the face of such disparity in numbers and resources, there was at times little Byzantine forces could do against major Arab invasions. Byzantine diplomacy represented a constant search for ways to divert Arab forces and for allies drawn from the nomadic steppe world north of the Caucasus and Black Sea, the only military powers capable of meeting the Caliphate on equal terms. The Khazar Empire was long the bulwark of this approach; it was in the wake of the Khazar collapse that Byzantine connections with the Rus—the Scandinavian rulers of Kiev who gave their name to what became Russia—took shape. When allies could not divert Arab attention, the Byzantine army had to perform a holding action.
Thus, campaign doctrine, not surprisingly, stressed indirect action and counseled avoiding battle unless the enemy had already been worn down and demoralized by ambushes and supply problems. Spies would attempt to warn of impending invasions, and scouts would track approaching forces as the troops from threatened areas were alerted and gathered—a timeconsuming process that made stopping invasions at the border fairly difficult. Smaller invasion forces moved too fast to be reliably intercepted, whereas larger but slower forces could prove too dangerous to confront directly with only a small local force. Campaigns thus became matters of guerrilla warfare. Byzantine forces would attempt to harass the enemy’s foragers, restricting their supplies. Detachments would be ambushed, potential campsites occupied ahead of the enemy’s arrival, and cities fortified to resist sudden assaults and restrict the enemy’s freedom of movement. The aim was to wear down the invaders, try to restrict the damage they did, and then reoccupy the land after the invaders left. Such a strategy took advantage of logistics and often consisted of little more than a waiting game: Arab armies large and small campaigned when fodder was available for their horses and resisted staying in Anatolia during the cold winters. The thematic armies thus proved bad at preventing Arab pillaging— a tactical concession to Arab strength—but good at preventing permanent conquest.
The insecurity of the Byzantine situation affected more than just strategy. Byzantine armies maintained the Roman practice of making fortified camps while marching. Laid out in a square, the camps would be made defensible, especially when an enemy force was in the area, with a ditch. The earth from the ditch was used to make a wall reinforced by a shield palisade. On the march, the square formation of the camp translated into a square infantry formation guarding the baggage train and guarded, in turn, by cavalry units. If a battle threatened, the infantry square became the focus of the army’s deployment, with the baggage sent to the rear and the cavalry now shielded inside the infantry.
The system did a remarkable job of preserving the empire against heavy odds, but it never stopped the pillaging and major invasions. The security of the empire was only really assured by the successful defense of Constantinople in 718 and the subsequent shift in Muslim priorities after the Abbasid revolution and the founding of Baghdad. The ninth-century political fragmentation of the Muslim world then leveled the playing field considerably along the Byzantine frontier.
Creation of the Tagmatic Forces At the accession of Constantine V in 741, the leader of the Opsikion Theme led an uprising that took two years to crush. The fifth revolt by this theme alone since Heraclius’s reign, it highlighted the danger of basing a large thematic army so close to the capital. Constantine responded by breaking up the Opsikion Theme into several smaller themes and by creating (partly from Opsikion soldiers) standing full-time units called tagmata based in and around the capital. Created from old units that had for centuries been ceremonial palace guards, the tagmata became the elite core of the Byzantine army. They received not only salary and lands but arms, equipment, rations, horses, and fodder from the government. Two units of infantry guarded the walls of the Imperial Palace and defended the City; a third took charge of the central baggage train and support services; and three elite cavalry units gave the emperor a personal army that counterbalanced the political weight of the themes. The tagmatic forces immediately proved their worth on campaign as well, re-creating an offensive capability for the Byzantine army. Constantine launched a successful raid of the Caliphate in 745, spearheaded by the tagmata. Tagmatic forces also contributed to Byzantine conquests in Greece and Macedonia, though a new enemy, the Bulgars, soon disputed the region.
The tagmata differed from the thematic forces in being full-time professionals with higher standards of equipment and training. But they were organized similarly and fought side by side with thematic forces. They began to provide Byzantium with offensive capability and reduced the incidence of rebellion by thematic generals. However, the tagmata themselves became a political force: Constantine may have created them in part to enforce his Iconoclastic religious policies in the capital, and subsequent emperors had to take account of tagmatic interests in their policies. And Byzantium remained generally on the defensive for another century after the tagmata were created. Only in the mid-800s would a series of developments begin to alter the empire’s grand strategy.
The founding of the tagmata coincided with the beginnings of a period of demographic and economic growth in the empire. Outbreaks of plague, which had struck periodically since Justinian’s reign, ceased, and Arab raids decreased somewhat in frequency and destructiveness. The population began to grow, and the government found its income improving. Around 840, in the wake of a major Arab invasion and revolts among the thematic forces, the emperor Theophilus took advantage of the empire’s resources to improve the army. He added to its numbers, partly by settling a large group of religious rebels from the Caliphate throughout the themes and enrolling them in the thematic forces. He probably doubled the pay of the whole army, and he established small border districts at the key passes through the Taurus range, strengthening the forward-reaction capabilities of the army at the frontiers.
Theophilus’s reforms seem to have immediately improved the morale and performance of the army. The interior of Asia Minor was largely secured against raiders, further encouraging demographic and economic recovery. Byzantine forces began consistently to go on the offensive against the Muslims to the east and southeast, against the Bulgars in the Balkans, and even in southern Italy and against Muslim naval forces based on Crete. The offensives were still limited in scope—several centuries of defensive mentality would not disappear overnight—and did not always succeed. But the pace picked up steadily from the founding of the Macedonian dynasty by Basil I in 867 and peaked between 963 and 976 under the emperors Nicephoras Phocas and John Tzimisces. The move to an offensive posture had significant implications in a number of areas.
Offensives reemphasized the connection of religion and warfare, though in different ways on the empire’s two fronts. Against Muslim forces, a form of holy war intensified from the Christian side, as the Byzantines generally proved resistant to allowing a Muslim population to remain in areas added to the empire. This often involved the expulsion of Muslims from areas not already depopulated by Byzantine raiding, though some groups converted to Christianity and joined the empire. In the Balkans, Byzantine military action became part of a more general cultural offensive, as first the Bulgars and then the Russians were converted to the Orthodox Church, though conversion by no means secured peace with these groups. Such conversions did expand the scope of a Byzantine commonwealth that reached well beyond the actual borders of the empire for the first time.
Offensives also offset the increased cost of the army to some extent. Offensive campaigns allowed Byzantine armies to live off the resources of their enemies and to reverse the flow of plunder to the empire’s benefit. And the naval offensive in the Aegean (see Chapter 10) cleared Muslim pirates from the seas and made trade more secure and so profitable.
Offensive warfare also affected the organization of the army and the balance of the forces within it. The tagmatic forces, as full-time professionals, were more valuable for offensive campaigns than the thematic forces, and this period saw several new tagmata created. The tagmatic forces were divided into eastern and western units and were often now stationed in the provinces, closer to theaters of action. The thematic forces, on the other hand, tended to be called out less often than before, and more selectively: Tenth-century military manuals advise picking the best men from a muster of provincials and recognizing specialties among the forces available— Armenians provided the best heavy infantry, for example. (See the Sources box “Byzantine Military Culture” for more details.)
The ultimate tactical expression of the new Byzantine offensive capability came with Nicephoras Phocas’s creation of a special unit of heavy cavalry, the kataphraktoi, or cataphracts. This unit, probably no more than about 500 strong, consisted of men who wore mail body armor from head to foot and rode horses covered with hardened hide armor that came down around the horses’ knees. Armed with maces and swords, and supported by lancers and horse-archers, they were intended as an irresistible shock force on the battlefield. They formed up in a blunt wedge formation and aimed their charge, at the crucial point of a battle, at the enemy commander and the heavy infantry forces around him. The charge, executed at a trot, depended as much on its psychological effect in terrorizing the target as it did on heavy armor and weapons to smash resistance, and it required considerable discipline on the part of the cataphracts themselves. Launching the attack at the enemy commander reflected a recognition that battles were often won by the death or flight of the enemy general. The cataphracts led conquests of Antioch, Syria, and northern Palestine under Nicephoras Phocas and John Tzimisces.
The increased importance of tagmatic forces and the trend toward selectivity in calling up the themes reinforced the effects of internal peace on interior themes, whose troops began to lose their military training and value. This provided further scope for economizing on costs and increasing revenues as the government began collecting payments from some thematic soldiers in lieu of their service in person, using the income to pay the tagmata. But the decay of the thematic forces held potential dangers and was connected to deeper social transformations stimulated by offensive warfare. The military aristocracy of the provinces, who held most of the positions of command in the increasingly numerous themes and the tagmata, and whose household retainers were often a major part of the tagmata, posed the biggest threat. As the population increased and the empire became more secure, land became more valuable, and the class interests of the aristocracy came into conflict with the interests of the central government. In addition, the extensive reconquest of the Near East that the military aristocrats seemingly envisioned threatened the dominance of Constantinople and its civil elite within the empire.
Basil II fought hard against this trend. He secured his throne only with the help of the Varangian Guard, a body of 6000 Scandinavian-Russian heavy infantry hired en masse, against the eastern tagmata, and dependence on bodies of foreign mercenaries increasingly characterized the Byzantine army thereafter. Save for completing the conquest of Bulgaria, which kept eastern forces busy away from their bases of power, he largely called a halt to expansion, especially eastward. The triumph of Constantinopolitan interests under Basil came at a cost, however.
By 1025, the Byzantine Empire was larger than it had been since the days of Heraclius, prosperous, and much more powerful militarily than any of its neighbors. Yet fifty years later, the empire and its army were irretrievably damaged. What happened?
The empire back into Roman times had always been dependent on strong leadership for military success. The worst foreign invasions and defeats almost always came in the wake of civil wars, succession crises, or rebellions that weakened and distracted the empire’s armed forces. The fifty years after Basil II’s death saw just such a period of disputed successions and weak, nonmilitary emperors and empresses, the effects of which compounded ongoing structural problems. Through 1042, the empire remained generally successful in its wars and even expanded its influence in Italy. But then a serious decline set in.
The army in 1042 was bloated, with far more men on the payroll than there were effectives. A successful military emperor, with the support of the active army, could probably have decommissioned the least useful units and cut back the pay of others. But the army as an institution resisted such measures from less proven leaders. Cuts therefore tended to come in the form of lighter coins or debased currency, which reduced the entire army’s effective pay, and neglect of the armed forces as a whole. This led to revolts by generals and the aristocracy of the provinces. The emperors between 1042 and 1067, mistrustful of the aristocracy and army, relied increasingly on foreign mercenaries for their personal military support. Constantine X did decommission a large group of thematic forces around 1050, releasing them from service in exchange for a tax. But because of his fear of revolt by active soldiers, he dismissed not the rusty interior themes but the most active ones, in the Armenian frontier provinces—precisely the region now facing a dangerous new threat, the Seljuk Turks.
A competent military leader, Romanus Diogenes, took the throne in 1067 and set about desperately trying to retrain the army. Attempting to stabilize the eastern frontier, he met the Turks at Manzikert in 1071 with a mixed force of mercenary, thematic, and tagmatic troops. However, treachery by relatives of the late Constantine X led to his defeat and capture. Civil war broke out, and over the next decade the Turks were allowed to overrun almost all of Asia Minor. The entire army, themes and tagmata, disintegrated. The last western tagmata fell fighting the Normans at Dyrrhachium in 1081 under Alexius I Comnenus.
Alexius would manage to rebuild the empire after 1081. But he could not rebuild the army. Units that could trace their history back 1000 years ceased to exist, and, with their end, the direct line of Roman military tradition also died out.
The continuity and unusual self-consciousness of Byzantine military culture was expressed partly in a series of military manuals that continued a late Roman tradition of theoretical and practical writing about military organization and war. Often written by emperors, the manuals explained unit structures and command hierarchies, gave advice on strategy and campaigning, and laid out tactical precepts. Attention was paid to the place of war among the various tools available to the empire in dealing with foreign foes, including diplomacy, bribery, and trickery. Particular attention was given to the unique characteristics of the different enemies the empire faced—something most premodern military writing did not do. The combination of antiquarian form and vocabulary ("Romans,” for example, remained the Byzantine word for themselves) with adaptation to new foes and conditions that the manuals show symbolize the continuity and flexibility of the whole Byzantine military tradition.
[Maurice, Strategy (c. 600)] Warfare is like hunting. Wild animals are taken by scouting, by nets, by lying in wait, by stalking, by circling around, and by other such strategems rather than by sheer force. In waging war we should proceed in the same way, whether the enemy be many or few. To try simply to overpower the enemy in the open, hand to hand and face to face, even though you might appear to win, is an enterprise which is very risky and can result in serious harm. Apart from extreme emergency, it is ridiculous to try to gain a victory which is so costly and brings only empty glory. . . .
[Leo VI, Tactics (c. 900)] As regards the Turkish nation, it is very numerous, sets little store by objects of luxury and ease, and devotes itself only to war and to making itself redoubtable in combat. . . . They are much given to discharging arrows from horseback. They take with them a quantity of mares and cows, whose milk they drink. They do not camp, like the Romans, in redoubts; rather, up to the actual day of fighting, they are separated into tribes and families. They post their guards far away and so thickly that they cannot be easily taken by surprise. . . . In their order of battle, they do not divide their army into three parts, as the Romans do. . . . They like to fight from a distance, set ambushes, simulate flight, disperse, and suddenly come back to charge. . . . With regard to the Franks, they are brave and daring almost to the point of foolhardiness. . . . They do not form up for battle as the Romans do, by companies and battalions, but by tribes and families. Those bound by friendship, and by a sort of brotherhood, also join together. . . . [An] excellent tactic is to attack them at night with archers, because they camp separately and dispersed. . . . I now move on to the Saracens, ever our enemies. . . . They blaspheme against Christ, whom they do not regard as true God and Savior of the world. . . . We who follow a holy divine law detest their impiety and make war on them to support the faith. . . . Their order of battle is a long square, set back everywhere and very difficult to break into. They use this pattern in marches as in battles. In fact, they imitate the Romans in many of the usages of war and methods of attack, which they have learned from us.
[Nicephoras Phocas, Military Precepts (c. 965)] As the enemy draws near, the entire contingent of the host, every last one of them, must say the invincible prayer proper to Christians, “Lord Jesus Christ, our God, have mercy on us, Amen,” and in this way let them begin their advance against the enemy, calmly proceeding in formation at the prescribed pace without making the slightest commotion or sound. . . . It is necessary, before all else, to check and see in what place the enemy commander happens to be and aim the triangular formation of the cataphracts directly at him, with the two units on either side of it, the outflankers. . . . The cataphracts and the two units on either side of them must remain in formation while our units make their attack against them. Should the enemy remain in formation while our units make their attack against them, as soon as the enemy’s arrows begin to be launched against the front of the triangular formation of the cata- phracts, our archers must strike back at the enemy with their arrows. Then the front of the triangular formation must move in proper formation at a trotting pace and smash into the position of the enemy commander while the outflankers on the outside encircle the enemy as far as possible and the other two units proceed on both flanks with perfect precision and evenness with the rear ranks of the cataphracts without getting too far ahead or breaking rank in any way. With the aid of God and through the intercession of His immaculate Mother the enemy will be overcome and give way to flight.