Basic Principles of Byzantine Strategy

Basic Principles of Byzantine Strategy

Basic Principles

Byzantine emperor Leo had defined strategy as utilization of theory and practice in adjusting to realities of warfare. Byzantine concept of strategy encompasses all aspects of warfare – everything that is today covered under strategy, operations, tactics, logistics and geography. Byzantines did not compartmentalize the skillset, as is done today.

Byzantine emperors were, as a rule, keenly aware of the Empire’s precarious position and a lack of resources. This meant that open conflict was avoided whenever possible – diplomacy was the first answer. Aims of diplomacy could be very different: forging alliances, intelligence activity, controlling client states and peace agreements. At times, diplomacy was used as a cover for other aims, such as attempt to assassinate Atilla in 449 AD.

Barbarians would be bought with gifts. And if enemies could not be negotiated with, alliance would be sought with other states and groups that had border with said enemies, but not with the Empire. Diplomats also acted as spies, collecting information and bribing individuals. Overall, the Empire had no formal strategic planning, yet its experiences from 4th century onwards had with time formed into an informal but coherent strategic doctrine which can be followed through all of Byzantine military manuals.

Unlike the modern world, there was no distinction between the military, diplomatic and political spheres and actions. Consequence of this is that the system as such supports military response to a political question. Tactical issues impact strategy, and both impact politics as well.

The primary goal of any strategy is to survive, as well as to maintain the freedom of action while denying this same freedom to the enemy. Because strategy is product of the mind, and one of main aims of strategy is to disrupt opponent’s strategy, material advantage is not a guarantee of achieving strategic goal(s).

Several important principles of Byzantine strategy can be specifically identified.

If you want peace, prepare for war

This principle is not something the Empire always followed – and when it did not, outcome was always catastrophic. Cutting off support to Ghassanids may have helped alleviate short-term financial concerns. But in the long term, it removed the best shield against desert nomads, and allowed newly Islamized Arabs to easily sweep aside all defences, conquering Empire’s Levantine and North African provinces. Argument could even be made that the Empire would not have fallen at all had it not been stingy with support for Ghassanids, but such long-term predictions are incredibly difficult to make properly.

At any rate, Byzantines did usually understand that peace is nothing but a period of recuperation between two wars. Starting with fourth century, and seventh century at the latest, the entire Byzantine society was geared for war. This included obvious things, such as a professional military and its logistical apparatus. Less obvious were the records of past conflicts and past enemies, which Byzantines kept in order to make informed decisions.

War is not only material

Byzantines considered themselves the inheritors of the Christian empire, and protectors of Christianity. War, being sinful, allowed other forms of sinful behaviour such as lying and cheating, but the war itself should always be just.

Psychological aspect of war was both keenly felt and closely intertwined with religion. Soldiers were followed by priests, who also acted as makeshift psychiatrists, and holy icons served as military banners. Dead received respectful burials – but at night, so that the enemy could not determine their number. Wounded were cared for. Family members and friends served together in units in order to help improve cohesion. Commanders were required to closely observe psychological and emotional condition of troops under their command, increase morale, and put down rumors and ill omens.

Whenever possible, rumors, disinformations and bribes were to be used to confound the enemy. Enemy commanders or select individuals would be sent gifts to sow doubts, and enemy abilities, habits and mentality were closely studied. But this did not always work: the sack of Constantinople was caused in part by deep misunderstanding of Western European mentality by the Byzantines.

Seek allies and turn enemies into allies

Much like they did before the fall of the Western Empire, Byzantines had maintained diplomatic links with groups on their borders, and tried to establish alliances. Berbers in North Africa and Ghassanids in Arabia were extremely important in maintaining the security of African and Arabian provinces of the Empire, respectively. Alliance with Bulgarians may have saved the Constantinople from the siege in 717., and Khazars were important allies against Muslims during 7th and 8th centuries. Venice was an important ally in securing Empire’s maritime position, especially in the Adriatic. In general, the Empire was always on a lookout for allies.

Yet this was not always successful. Main problem seems to be that the Byzantines simply could not understand the West, or realize that Western Europe was leaving barbarism. They thus continued with their old diplomacy which was adjusted for dealing with barbarian tribes, and also very condescending. This was extremely insulting to Westerners, and helped cause the Fourth Crusade.

Fourth Crusade – a cultural failure

Likewise, there were cases when the Empire basically abandoned allies – always with catastrophic consequences. Arab conquest of the Middle East was enabled in part by weakness of the Ghassanids, caused by internal strife but also by cessation of Byzantine support in the wake of Byzantine-Persian war. The loss of Anatolia in 11th century had been preceded by Byzantine absorption of multiple satellite states during and after the rule of Basil II.

Avoid direct contest of strength

Between 6th and 15th century, only during the Macedonian dynasty (867. – 1056., though decline started in 1025.) was the Empire in position to defeat its enemies by frontal attacks. Ever since 6th century, the Empire was in a state of constant defense against overwhelming threats. After 7th century, border defense was impossible, and major defeats inevitable. Only in 10th century, under rule of Nikephoros II. Phokas, does the Empire shift to a definitely offensive posture. Yet Nikephoros was also the author – or at least commissioned writing – of a manual On Skirmishing (Peri Paradromes, latinized as De Velitatione Bellica), which was based on Byzantine experiences in defensive warfare and is one of the most important sources on guerilla warfare in general.

Byzantine strategy itself was largely based on Strategikon of the emperor Maurice. Primary advice given by Maurice was that direct confrontation was to be avoided. Warfare is to be treated much like hunting, utilizing reconnaissance, ambushes, tracking, encirclements and other strategems. Same approach was to be utilized regardless of how powerful the opponent was. Commander had to aim to utilize enemy’s weaknesses against him. Numerous army was to be cut off from supplies. If enemy army was diverse – comprised of many ethnic groups – then aim should be to cause strife between them. If the enemy lacked discipline, battle should be delayed so that they lose attention. Whenever possible, enemy army should be weakened by applying one or more strategems before being engaged and destroyed in open battle.

Maurice’s Strategikon

Attacks themselves should be carried out quickly, before the enemy could prepare. In order to increase probability of success, all measures should be used. Enemy could be offered a truce just before an attack was launched, or attack could be delayed to provide him a false sense of safety. No matter what, both sides should be allowed a room to retreat: an opponent with no exit will provide stiff resistance, yet commander himself should always be aware of a possibility of defeat. Proper supply and intelligence are crucial, which necessitates close cooperation with the local populace. Enemy supplies should be cut off, and any attack responded to with a counterattack at the point where the enemy is weakest.

By applying these principles, Byzantine Empire managed to retain ability to return control over areas temporarily conquered by the Arabs as well as the ability to keep fortifications manned at all times. As a result, Arabs were not able to establish any permanent presence in Anatolia, and Turks could only do so because the theme system had been disbanded.

Utilize defense in depth

Roman defences had always utilized geography, but proper defense in depth approach was only established during the Dark Ages. After 7th century, or perhaps even earlier, both Balkans and Anatolia were littered with fortifications which provided both control points and refuge for the local population. Waterways were utilized to transfer troops into enemy’s rear, while mountain passess offered natural choke points. But the choke points were not foundation of Byzantine strategy. Main aim was to isolate and destroy enemy army that had already entered the territory of the Empire: Byzantine strategy had accepted failure of border-based defense as inevitable. Invading armies were shadowed while the land was stripped of resources, making it impossible for the enemy armies to resupply themselves as their foraging parties were hunted down and destroyed.

Initial Arab strategy called for the conquest of Constantinople, forcing them onto long marches through Anatolia. Particularly difficult was situation in 650s and 660s. In 654., Arab field army and fleet invaded the Empire, advancing rapidly through Asia Minor until they reached the capital without much difficulty. While the siege failed, there was absolutely no resistence by armies or population of Asia Minor to the attack:

When he (Mu‘āwiya) penetrated the whole land, all the inhabitants of the country submitted to him, those on the coast and in the mountains and on the plains. (Sebeos)

People readily submitted to Arab rule, and only destruction of Arab forces in siege of Constantinople saved the Empire. Yet Arabs themselves had only acted in Asia Minor to secure a safe route towards Constantinople: the clear assumption was that conquest of the Empire could only be achieved by conquering its capital.

But since 660s, there was a general resistance to Arab invasions within the Empire. Second attack on Constantinople was launched in 667. – 669.. But the Arab army had been advancing towards Constantinople since 663/4, yet blockade of the city only began in 667. This was not a consequence of sudden strenghtening of Byzantine defences, but rather had several causes.

There was a major change in Arab strategy. Rather than assuming that conquest of Constantinople will result in immediate fall of the Empire, in 660s the Arabs took a long time to devastate defences of Anatolia. Many cities and forts were attacked and temporarily captured, and inhabitants taken captive – especially in the rich and densely populated western Anatolia.

Byzantine themata 650 – 750 AD

Byzantines themselves relied on terrain and fortifications. During 660s – as early as 663. – Arabs were forced to take cities by force. Only Amorion surrendered, while Pessinos, Kios, Pergamon and Smyrna had to be captured. This shows that cities had been fortified and prepared for siege, as a settlement with no fortifications will not have risked resistance. And where in 650s the inhabitants of Asia Minor had easily accepted the Arabs, there was – as noted – pronounced and active resistance. Several cities and forts successfuly resisted Arabs attacks and sieges. Further, active resistance was carried out not only by the army but by the local population as well. All of this meant that the Arab army had to subdue the Asia Minor before heading out for Constantinople.

Failure of Arab siege in 654. was likely key in Byzantine resistance, as Byzantines saw it as secured by the grace of God. This convinced them that God did not abandon them, and thus motivated active resistance against the invading armies. As early as 654., Byzantine field army had defeated the Arab army stationed in Cappadocia and forced it to flee. While the following counterattacks by Byzantines failed, the clear message was that the Arabs were no longer seen as invincible.

This had the effect of eventually making such invasions unsustainable and forcing the Caliphate to limit their strategy to raiding border areas. In the short term, Umayyad offensives did resume. Muslim forces took Carthage in 698., and in the following years annexed the rest of Byzantine North Africa. But resistance against Arab forces in Anatolia during 717.-718. was extensive, and became even more so during later invasions. Byzantine thematic system established by the late 8th century in fact could not exist without wide cooperation and confidence of inhabitants of the region. In fact, it was the morale factors involved in raising and maintaining the thematic forces that were more important in preserving the Empire than the system’s raw military effectiveness. When thematic system was abandoned and Constantine X Doukas disbanded 50 000 strong Armenian army, the Empire had lost most of its strategic depth despite the physical extent of the territory remaining the same. The result was relatively easy conquest of Anatolia by Turks.

Fight small wars

Byzantine strategy had avoided decisive battles since 5th century, as defeats at Adrianople in 378., against Atilla in 443. and Vandals in 468. had illustrated the danger of a decisive battle. Battle of Yarmouk in 636. was an exception in Byzantine aim at avoiding decisive battles, and it only reinforced the rule. Introduction of themes under Constans during 650s and 660s had essentially hard-baked this tendency, as offensive capabilites of Byzantine army had been sharply limited by these reforms. Therefore, from 7th to 9th century, warfare was focused primarily on raiding and maintaining forces capable of threatening the enemy. Small scale actions and maneuver were used to avoid attrition.

This strategy however was never a hard rule. Imperial forces did on occasion fight large-scale engagements, if favorable conditions could be assured. But in first, dark centuries, this was an exceptionally rare occurrence. Only from late 9th and until 11th century do Byzantine armies actively seek pitched battles, relying on their discipline, training and coordination to carry the day. Not surprisingly, this is also the time of decline in the theme system – a decline which would eventually doom the Empire.

Divide and rule

Encouraging divisions and conflicts within the enemy ranks was a standard Byzantine strategy. During peace or war, Byzantines sought allies among neutral parties and within enemy ranks alike. During war against the Abassyds, Emperor Theophilos managed to secure services of Persian Khurramites. In campaign against Pechenegs in 1122., John II used the truce to entice a portion of the enemies to switch sides. The rest was crushed later.

Second aspect of this strategy was avoiding this same thing happening to the Empire itself. Basil II and John II Comnenos were more successful than most other emperors in their dynasties simply because they had managed to avoid fighting against more than one opponent. John Comnen also focused on the eastern front, and avoided open battles while focusing on siege warfare.

Naval Strategy

Roman Empire used to have a relatively powerful navy, as did Byzantine Empire during some periods. But the needs of defending Anatolia meant that not much could be spared for the navy, and so already by 9th century the Empire had to rely on Venice for some tasks. By 13th century, Venetian navy had marked the end of the Byzantine Empire as a Mediterranean economic and military power. Already by 12th century the entire trade of the Empire had been carried out through middlemanship of Italian – mostly Venetian – traders, who had also received major benefits while Byzantine traders were heavily controlled and limited.

This was consequence less of lack of investment in the navy and more of a lack of consistency in said investment. Constans II had founded naval themes in 650s and 660s, but in 667 Rhodos had been lost and Cyprus in 670. Only in 875 under Basil I did Byzantine Empire again contest the sea, and by 968 Nikephoros Phokas could boast that only he had the navy capable of attacking Otto I. But the navy fell victim of its own success: lack of threats meant that it was neglected, and by 1081 the Empire had to give Venice a Golden Bull in exchange for Venetian naval support. Only Manuel I Komnenos renewed the navy, and by 1171 Byzantine navy could match the Venice. But after his death in 1180 the navy again went neglected. By 1196, even pirates were an unmanageable threat, and by 1203 the Empire had basically no warships that could be put to sea in order to face the Western invasion. In the end, much like the thematic system itself, the navy was a victim of its own success.

Byzantine navy

During its existence, main advantage of the Byzantine Navy over its opponents was the defensive nature of Byzantine strategy. Tactical abilities of the navy were average, but becase enemies always had to fight close to Byzantine shores, they were vulnerable to ambushes and could not recuperate losses in ships and manpower as well as the Byzantines could. Still, the main purpose of the navy was to enable amphibious attacks and seaborne maneuvers by ground forces, especially since galleys relied on control of the shore to be effective – a war galley had endurance of no more than a few days.

Overall, while Byzantine abandonment of the navy can be understood through primacy of land-based threat and fiscal limitations, the consequences of neglect of the naval power were still catastrophic. As Byzantine experiences had shown, navy is a long-term investment and cannot be created in haste.

Espionage and diplomacy

Byzantine espionage was both tactical and strategic. In strategic terms, Byzantines relied on a network of spies and scouts. Diplomats, emissaries, “secret friends” and traders all served a double duty as spies, with traders bringing the messages back to Constantinople. Many spies were themselves traders, living among middle to lower classes and with knowledge of the local language. When Muslim robber armies gathered on eastern borders in August, Romans would send traders and spies across the border.

This activity naturally informed Byzantine diplomacy. But over time, the task became more difficult. In early Middle Ages, most of Byzantine neighbors did not possess Roman legal and political structures. Thus they formed their internal structures with the help of the Empire, which Byzantines then used to incorporate them into a network of international relations controlled by the Byzantine Empire.

Yet relations with the West were seriously complicated by cultural differences. These were present from the beginnings: Charlemagne got crowned a Roman Emperor because of a conflict between the Empire and the papacy. And even when the Byzantines sought help from the West, cultural differences were an issue: Byzantines asked for mercenaries and received the First Crusade instead. And cultural differences only increased misunderstandings: Western culture was based on warfare, and the Empire was seen as weak, morally bankrupt and obsessed with the past. This Western unwillingness to try and understand the Empire put a lid on any possibility of stopping Muslim expansion in Anatolia.

And while Byzantine diplomacy had been initially very successful, steady evolution and advancement of the West soon began to sharply limit its possibilities. Western kingdoms were politically independent of each other, yet they were also connected through common culture, political system and loyalty to the Pope. Their common ethos, based around warfare, feudalism and Catholicism, meant that any attempts at cultural influence by the Empire were doomed to fail. Only money was successful in temporarily buying loyalty and services of the Westerners, but this could not last long. With time, Venice especially undermined foundations of the Empire and eventually captured Constantinople in 1204.


Money was one of primary means of propaganda, even since the antiquity. From 7th century onwards the coins have images of emperors as well as their successors, thus attempting to legitimize the succession. During rule of iconoclast emperors, portraits on avers had been apstract and lineralized, while the cross on revers had been replaced by a portrait of emperor or, later, his chosen successor. In 9th century icons reappear, and imperial portraits become realistic.

Basil II depicted as a saint

Iconoclasm itself had been introduced by Leo III in an attempt to bring the Empire closer to eastern Christians and potentially enable liberation of conquered areas. Secondary goal was weakening of monasteries that had grown rich at the expense of the state. Iconoclast policy was definitely abandoned after 843., and at the same time intellectual development occured – caesar Bardas founded university, while Basil I and his son Leo collected Roman laws in sixty books called Basilica. Rise of Constantinople caused hostility in Rome, which was reinforced by the importance that Constantinople had assigned to secular education.


As can be seen, Byzantines as a rule preferred a cautious approach. This was a consequence of both past experiences and limitations in resources that the Empire was subjected to. Yet while above principles were generally upheld by the Byzantines, it also has to be understood that there were many exceptions. Byzantines tended to play a cautious game – or at least as much as current emperor’s personality allowed for – but this does not mean they always avoided direct contests of strength. Indeed, they would at times try to force such, if they felt that balance of power favored them. One should also avoid reading too much into it: even modern states often do not have a coherent strategy, and pre-modern states could produce it even less reliably. This can be easily seen with Byzantine Empire itself, as even during the Middle Empire there were multiple cases where the emperors abandoned the cautious approach. Nikephoros I launched an ill-advised offensive into Bulgaria, which was prepared hastily and resulted in a disaster. Similar mistake resulted in Battle of Manzikert in 1071.

Still, such examples were usually found in 10th and 11th centuries, and very rarely before the 9th century. Thus it can be seen that Byzantines, once in a position to take the offensive, were not able to apply the hitherto utilized cautious approach. And while argument could be made that majority of manuals and experiences in irregular warfare apply to the eastern front, it must not be forgotten that foundations for irregular warfare were laid by the Strategikon of Maurice, a book written in response to barbarian invasions of the Balkans.


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