Reading: Justinian I and the rise of Byzantium

Christopher Brooks

The eastern half of the Roman Empire survived for 1,000 years after the fall of the western one. It carried on most of the traditions of Rome and added many new innovations in architecture, science, religion, and learning. It was truly one of the great civilizations of world history. And yet, as demonstrated in everything from college curricula to representations of ancient history in popular culture, the eastern empire, remembered as “Byzantium,” is not as well represented in the contemporary view of the past as is the earlier united Roman Empire. Why might that be?

The answer is probably this: like the western empire before it, Byzantium eventually collapsed. However, Byzantium did not just collapse, it was absorbed into a distinct culture with its own traditions: that of the Turkish Ottoman Empire. More to the point, the religious divide between Christians and Muslims, at least from the perspective of medieval Europeans, was so stark that Byzantium was “lost” to the tradition of Western Civilization in a way that the western empire was not. Even though the Ottoman Empire itself was a proudly “western” civilization, one that eagerly built on the prosperity of Byzantium after absorbing it, there is a (misguided) centuries-long legacy of distinguishing between the Byzantine – Ottoman culture of the east and the Roman – European medieval culture of the west.

Byzantine civilization’s origins are to be found in the decision by the emperor Constantine to found a new capital in the Greek village of Byzantium, renamed Constantinople (“Constantine’s city”). By the time the western empire fell, the center of power in the Roman Empire had long since shifted to the east: simply put, by the fifth century CE the majority of wealth and power was concentrated in the eastern half of the empire. The people of Constantinople and the eastern empire did not call it “Byzantium” or themselves “Byzantines” – they continued to refer to themselves as “Romans” long after Rome itself was permanently outside of their territory and control.

After the fall of the western empire, the new Germanic kings acknowledged the authority of the emperor in Constantinople. They were formally his vassals (lords in his service) and he remained the emperor of the entire Roman Empire in name. At least until the Byzantine Empire began to decline in the seventh century, this was not just a convenient fiction. Even the Franks, who ruled a kingdom on the other end of Europe furthest from the reach of Constantinople, lived in genuine fear of a Byzantine invasion since the treaties they had established with Constantinople were full of loopholes and could be repudiated by any given emperor.

East versus West

Why was it that the west had fallen into political fragmentation while the east remained rich, powerful, and united? There are a few major reasons. First, Constantinople itself played a major role in the power and wealth of the east. Whereas Rome had shrunk steadily over the years, especially after its sacking in 410 and the move of the western imperial government to the Italian city of Ravenna (which was more easily defensible), Constantinople had somewhere around 500,000 residents. That can be compared to the capital of the Gothic kingdom of Gaul, Toulouse, which had 15,000 (which was a large city by the standards of the time for western Europe!). Not only was Constantinople impregnable to invaders, but its population of proud Romans repeatedly massacred barbarians who tried to seize power, and they deposed unpopular emperors who tried to rule as military tyrants rather than true emperors possessing sufficient Roman “virtue.”


The Roman Empire after its political division between east and west under Diocletian. From the third through fifth centuries CE, the eastern part of the empire became the true locus of power and wealth, and as of the late fifth century, the entire western half “fell” to barbarian invasions.

The east had long been the richest part of the empire, and because of its efficient bureaucracy and tax-collecting systems, much more wealth flowed into the imperial coffers in the east than it did in the west. Each year, the imperial government in Constantinople brought in roughly 270,000 pounds of gold in tax revenue, as compared to about 20,000 in the west. This made vastly better-equipped, trained, and provisioned armies possible in the east. Furthermore, the west was still dominated by various families of unbelievably rich Roman elites who undermined the power, authority, and financial solvency of the western imperial government by refusing to sacrifice their own prerogatives in the name of a stronger united empire. In the east, while nobles were certainly rich and powerful, they were nowhere near as powerful as their western counterparts.

There is another factor to consider, one that is more difficult to pin down than the amount of tax revenue or the existence of Constantinople’s walls. Simply put, Roman identity – the degree to which social elites, soldiers, and possibly regular citizens considered themselves “Roman” and remained loyal to the Empire – seems to have been stronger in the east than the west. This might be explained by the reverse of the “vicious cycle” of defeat and vulnerability described in the last chapter regarding the west. In the east, the strength of the capital, the success of the armies, and the allegiance of elites to Rome as an idea encouraged the continued strength of Roman identity. Even if poor farmers still had little to thank the Roman state for in their daily lives, their farms were intact and local leaders were still Roman, not Gothic or Frankish or Vandal.

Lastly, the east enjoyed a simple stroke of good luck in the threats it faced from outside of the borders: the barbarians went west and Persia did not launch major invasions. The initial Gothic uprising that sparked the beginning of the end for the west was in the Balkans, but the Goths were then convinced to go west. Subsequent invasions from Central Europe were directed at the west. Even though the Huns were from the steppes of Central Asia, they established their (short-lived) empire in the west. Eastern Roman armies had to repulse threats and maintain the borders, but they did not face the overwhelming odds of their western Roman counterparts. Finally, despite Persia’s overall strength and coherence, there was a lull in Persian militarism that lasted through the entire fifth century.


The most important early emperor of Byzantium was Justinian, who ruled from 527 to 565. Justinian was the last Roman emperor to speak Latin as his native tongue; afterwards, all emperors spoke Greek. He is remembered for being both an incredibly fervent Christian, a major military leader, the sponsor of some of the most beautiful and enduring Byzantine architecture in existence, and the husband of probably the most powerful empress in the history of the empire, a former actress and courtesan named Theodora.

Justinian created a tradition that was to last for all of Byzantine history: that of the emperor being both the spiritual leader of the Christian Church and the secular ruler of the empire itself. By the time the western empire fell, the archbishops of Rome had begun their attempts to assert their authority over the church (they would not succeed even in the west for many centuries, however). Those claims were never accepted in the east, where it was the emperor who was responsible for laying down the final word on matters of religious doctrine. Justinian felt that it was his sacred duty as leader of the greatest Christian empire in the world to enforce religious uniformity among his subjects and to stamp out heresy. He called himself “beloved of Christ,” a title the later emperors would adopt as well. While he was never able to force all of his subjects to conform to Christian orthodoxy (especially in rural regions far from the capital city), he did launch a number of attacks and persecutory campaigns against heretical sects.

One aspect of Justinian’s focus on Christian purification was the destruction of the ancient traditions of paganism in Greece and the surrounding areas initiated by his Christian predecessors. The Olympics had already been shut down by the emperor Theodosius I back in 393 CE (he objected to their status as a pagan religious festival, not an athletic competition). Justinian insisted that all teachers and tutors convert to Christianity and renounce their teaching of the Greek classics; when they refused in 528, he shut down Plato’s Academy, functioning at that point for almost 1,000 years. (Many of the now-unemployed scholars fled to Persia, where they were welcomed by the Sasanian rulers.)

Justinian did not just enforce religious uniformity, he also imposed Roman law on all of his subjects. The empire had traditionally left local customs and laws alone so long as they did not interfere in the important business of tax collection, troop recruitment, and loyalty to the empire. Justinian saw Roman law as an aspect of Roman unity, however, and sought to stamp out other forms of law under his jurisdiction. He had legal experts go through the entire corpus of Roman law, weed out the contradictions, and figure out the laws that needed to be enforced. He codified this project in the Corpus Juris Civilis, which forms the direct textual antecedent for most of the legal systems still in use in Europe.

Theodora, who had come from decidedly humble origins as an entertainer, worked diligently both to free prostitutes from sexual slavery, expand the legal rights and protections of women, and protect children from infanticide. She was Justinian’s confidant and supporter throughout their lives together, helping to conceive of not just legal revisions, but the splendid new building projects they supervised in Constantinople. In a famous episode from early in Justinian’s reign, Theodora prevented Justinian and his advisors from fleeing from a massive riot against his rule, instead inspiring Justinian to order a counter-attack that may well have saved his reign. While most political marriages in Byzantium, as in practically every pre-modern society, had nothing whatsoever to do with love or even attraction, Theodora and Justinian clearly shared both genuine affection for one another and intellectual kinship.


The best-known surviving depiction of Justinian from a mosaic in Ravenna, Italy. In the mosaic, Justinian is dressed in the “royal purple,” a color reserved for the imperial family.

Justinian was intent on re-conquering the western empire from the Germanic kings that had taken over. He was equally interested in imposing Christian uniformity through the elimination of Christian heresies like Arianism. He sent a brilliant general, Belisarius, to Vandal-controlled North Africa in 533 with a fairly small force of soldiers and cavalry, and within a year Belisarius soundly defeated the Vandal army and retook North Africa for the empire. From there, Justinian dispatched Belisarius and his force to Italy to seize it from the Ostrogoths.

What followed was twenty years of war between the Byzantines and the Gothic kingdom of Italy. The Goths had won over the support of most Italians through fair rule and reasonable levels of taxation, and most Italians thus fought against the Byzantines, even though the latter represented the legitimate Roman government. In the end, the Byzantines succeeded in destroying the Gothic kingdom and retaking Italy, but the war both crippled the Italian economy and drained the Byzantine coffers. Italy was left devastated; it was the Byzantine invasion, not the “fall of Rome” earlier, that crippled the Italian economy until the late Middle Ages.

In 542, during the midst of the Italian campaign, a horrendous plague (the “Plague of Justinian”) killed off half the population of Constantinople and one-third of the empire’s population as a whole. This had an obvious impact on military recruiting and morale. In the long term, the more important impact of the plague was in severing many of the trade ties between the two halves of the empire. Economies in the west became more localized and less connected to long-distance trade, which ultimately impoverished them. A few years earlier, in 536, a major volcanic eruption in Iceland spewed so much debris in the air that Europe’s climate cooled considerably with “years without a summer,” badly undermining the economy as well. Thus, war, natural disaster, and disease helped usher in the bleakest period of the Middle Ages in the west, as well as leading to a strong economic and cultural division between west and east.

Even as the Byzantine forces struggled to retake Italy, Justinian, like the emperors to follow him, had a huge problem on his eastern flank: the Persian Empire. Still ruled by the Sasanians, the Persians were sophisticated and well-organized rivals of the empire who had never been conquered by Rome. Ongoing wars with Persia represented the single greatest expense Justinian faced, even as he oversaw the campaigns in Italy. The Byzantines and Persians battled over Armenia, which was heavily populated, and Syria, which was very rich. Toward the end of his reign, Justinian simply made peace with the Persian king Khusro I by agreeing to pay an annual tribute of 30,000 gold coins a year. It was ultimately less expensive to spend huge sums of gold as bribes than it was to pay for the wars.

The problem with Justinian’s wars, both the reconquest in the west and the ongoing battles with the Persians in the east, was that they were enormously expensive. Because his forces won enough battles to consistently loot, and because the empire was relatively stable and prosperous under his reign, he was able to sustain these efforts during his lifetime. After he died, however, Byzantium slowly re-lost its conquests in the west to another round of Germanic invasions, and the Persians pressed steadily on the eastern territories as well.

Division and Decline

The relative political and religious unity Justinian’s campaigns brought back to Byzantium declined steadily after his death. For almost 1,000 years, the two kinds of Christianity – later called “Catholic” and “Eastern Orthodox,” although both terms speak to the idea of one universal and correct form of Christian doctrine – were sundered by the great political divisions between the Germanic kingdoms of the west and Byzantium itself in the east. In Eastern Europe, small kingdoms and poor farmers played host to rival missionaries preaching the slightly-different versions of Christianity. Trade existed, but was never as strong as it had been during the days of the united empire.

Byzantium’s major ongoing problem was that it faced a seemingly endless series of external threats. Byzantium was surrounded by hostile states and groups for most of its existence, and it slowly but steadily lost territory until it was little more than the city of Constantinople and its immediate territories. It is important to remember, however, that this process took many centuries, longer even than the Roman Empire itself had lasted in the west. During that time, Constantinople was one of the largest and most remarkable cities on the planet, with half a million people and trade goods and visitors from as far away as Scandinavia, Africa, and England. Its people believed that their empire and their emperor were preserved by God Himself as the rightful seat of the Christian religion. Thanks to the resilience of its people, the prosperity of its trade networks, and the leadership of its emperors (the effective ones, anyway), Byzantium remained a major state and culture for centuries despite its long-term decline in power from the days of Justinian.

The most significant leader after Justinian was the emperor Heraclius (r. 610 – 641). He was originally a governor who returned from his post in Africa to seize the throne from a rival named Phocas in the midst of a Persian invasion. The empire was in such disarray at the time that the Persians seized Syria, Lebanon, and Egypt, cutting off a huge part of the food supply to Constantinople. In the process, the Persians even seized the “True Cross,” the cross on which (so Christians at the time believed) Christ Himself had been crucified, from its resting place in Jerusalem. Simultaneously, the Avars and Bulgars, steppe peoples related to the Huns, were pressing Byzantine territory from the north, and piracy was rife in the Mediterranean.

Heraclius managed to save the core of the empire, Anatolia and the Balkans, by recruiting free peasants to fight instead of relying on mercenaries. He also focused on Anatolia as the breadbasket of the empire, temporarily abandoning Egypt but keeping his people fed. He led Byzantine armies to seize back Jerusalem and the True Cross from the Persians, soundly defeating them in 628, and in 630 he personally returned the True Cross to its shrine in Jerusalem. The fighting during this period was often desperate – Constantinople itself was besieged by an allied force of Avars and Persians at one point – but in the end Heraclius managed to pull the empire back from the brink.

Despite his success in staving off disaster, however, a new threat to Byzantium was growing in the south. The very same year that Heraclius returned the True Cross to Jerusalem, the Islamic Prophet Muhammad returned to his native city of Mecca in the Arabian Peninsula with the first army of Muslims. Heraclius had no way of knowing it, but Byzantium would soon face a threat even greater than that of the Persians: the Arab caliphates (considered in the following chapter). Indeed, Heraclius himself was forced to lead Byzantium during the first wave of the Arab invasions, and despite his own leadership ability vital territories like Syria, Palestine, and Egypt were lost during his own lifetime (he died in 641, the same year that most of Egypt was conquered by the Arabs).

The City and the Emperors

A major factor in the success of Orthodox conversion among the Slavic peoples of Eastern Europe was the splendor of Constantinople itself. Numerous accounts survive of the sheer impact Constantinople’s size, prosperity, and beauty had on visitors. Constantinople was simply the largest, richest, and most glorious city in Europe and the Mediterranean region at the time. It enjoyed a cash economy, impregnable defensive fortifications, and abundant food thanks to the availability of Anatolian grain and fish from the Aegean Sea. Silkworms were smuggled out of China in roughly 550, at which point Constantinople became the heart of a European silk industry, an imperial monopoly which generated tremendous wealth. The entire economy was regulated by the imperial government through a system of guilds, which helped ensure steady tax revenues.


Constantinople was impregnable for centuries. Strong walls protected it in the west, and it was surrounded by cliffs leading down to the sea (and its ports) on all of the other sides.

Meanwhile, in the heart of the empire, the emperor held absolute authority. A complex and formal ranking system of nobles and courtiers, clothed in garments dyed specific colors to denote their respective ranks, separated the person of the emperor from supplicants and ambassadors. This was not just self-indulgence on the part of the emperors, of showing off for the sake of feeling important; this was part of the symbolism of power, of reaching out to a largely illiterate population with visible displays of authority.

The imperial bureaucracy held enormous power in Byzantium. Provincial elites would send their sons to Constantinople to study and obtain positions. Bribery was rife and nepotism was as common as talent in gaining positions; there was even an official list of maximum bribes that was published by the government itself. That said, the bureaucracy was somewhat like the ancient Egyptian class of scribes, men who maintained coherence and order within the government even when individual emperors were incompetent or palace intrigue rendered an emperor unable to focus on governance.

The imperial office controlled the minting of coins, still the standard currency as far away as France and England because the coins were reliably weighted and backed by the imperial government. The emperor’s office also controlled imperial monopolies on key industries like silk, which were hugely lucrative. It was illegal to try to compete with the imperial silk industry, so enormous profits were directed straight into the royal treasury.

Constantinople had as many as a million people in the late eighth century (as compared to no more than 15,000 in any “city” in western Europe), but there were many other rich cities within its empire. As a whole, Byzantium traded its high-quality finished goods to western Europe in return for raw materials like ore and foodstuffs. Despite its wars with its neighbors to the east and south, Byzantium also had major trade links with the Arab states.

Orthodox Christianity and Learning

To return to Orthodox Christianity, it was not just because Constantinople was at the center of the empire that Byzantines thought it had a special relationship with God. Its power was derived from the sheer number of churches and relics present in the city, which in turn represented an enormous amount of potentia (holy power). Byzantines believed that God oversaw Constantinople and that the Virgin Mary interceded before God on the behalf of the city. Many priests taught that Constantinople was the New Jerusalem that would be at the center of events during the second coming of Christ, rather than the actual Jerusalem.

The piety of the empire sometimes undermined secular learning, however. Over time, the church grew increasingly suspicious of learning that did not have either center on the Bible and religious instruction or have direct practical applications in crafts or engineering. Thus, there was a marked decline in scholarship throughout the empire. Eventually, the whole body of ancient Greek learning was concentrated in a small academic elite in Constantinople and a few other important Greek cities. What was later regarded as the founding body of thought of Western Civilization – ancient Greek philosophy and literature – was thus largely analyzed, translated, and recopied outside of Greece itself in the Arab kingdoms of the Middle Ages. Likewise, almost no one in Byzantium understood Latin well by the ninth century, so even Justinian’s law code was almost always referenced in a simplified Greek translation.

This was a period in which, in both the Arab kingdoms and in Byzantium, there was a bewildering mixture of language, place of origin, and religious affiliation. For example, a Christian in Syria, a subject of the Muslim Arab kingdoms by the eighth century, would be unable to speak to a Byzantine Christian, nor would she be welcomed in Constantinople since she was probably a Monophysite Christian (one of the many Christian heresies, at least from the Orthodox perspective) instead of an Orthodox one. Likewise, men in her family might find themselves enlisted to fight against Byzantium despite their Christian faith, with political allegiances outweighing religious ones.


One of the greatest religious controversies in the history of Christianity was iconoclasm, the breaking or destroying of icons. Iconoclasm was one of those phenomena that may seem almost ridiculously trivial in historical hindsight, but it had an enormous (and almost entirely negative) impact at the time. For people who believed in the constant intervention of God in the smallest of things, iconoclasm was an enormously important issue.

The conundrum that prompted iconoclasm was simple: if Byzantium was the holiest of states, watched over by the Virgin Mary and ruled by emperors who were the “beloved of God,” why was the empire declining? Just as Rome had fallen in the west, Byzantium was beset by enemies all around it, enemies who had the depressing tendency of crushing Byzantine armies and occasionally murdering its emperors. Byzantine priests repeatedly warned their congregations to repent of their sins, because it was sin that was undermining the empire’s survival. The emperor Leo III, who ruled from 717 – 741, decided to take action into his own hands. He forced communities of Jews in the empire to convert to Christianity, convinced that their presence was somehow angering God. He then went on to do something much more unprecedented than persecuting Jews: attacking icons.

Icons were (and are) one of the central aspects of Eastern Orthodox Christian worship. An icon is an image of a holy figure, almost always Christ, the Virgin Mary, or one of the saints, that is used as a focus of Christian worship both in churches and in homes. Byzantine icons were beautifully crafted and, in a largely illiterate society, were vitally important in the daily experience of most Christians. The problem was that it was a slippery slope from venerating God, Christ, and the saints “through” icons as symbols, versus actually worshiping the icons themselves as idols, something expressly forbidden in the Old Testament. Frankly, there is no question that thousands of believers did treat the icons as idols, as objects with potentia unto themselves, like relics.


A fourteenth-century icon of the Virgin Mary.

In 726, a volcano devastated the island of Santorini in the Aegean sea. Leo III took this as proof that icon veneration had gone too far, as some of his religious advisers had been telling him. He thus ordered the destruction of holy images, facing outright riots when workers tried to make good on his proclamation by removing icons of Christ affixed to the imperial palace. In the provinces, whole regions rose up in revolt when royal servants showed up and tried to destroy icons. In Rome, Pope Gregory II was appalled and excommunicated Leo. Leo, in turn, declared that the pope no longer had any religious authority in the empire, which for practical purposes meant the regions under Byzantine control in Italy, Sicily, and the Balkans.

The official ban of icons lasted until 843, over a century, before the emperors reversed it (it was an empress, named Theodora like the famous wife of Justinian centuries earlier, who led the charge to officially restore icons). The controversy weakened the empire by dividing it between iconoclasts loyal to the official policy of the emperors and traditionalists who venerated the icons, while the empire itself was still beset by invasions. Iconoclasm also lent itself to what would eventually become a permanent split between the eastern and western churches – Orthodoxy and Catholicism. The final and permanent split between the western and eastern churches, already de facto in place for centuries, was in 1054, when Pope Leo IX and Patriarch Michael I excommunicated each other after Michael refused to acknowledge Leo’s preeminence – this event cemented the “Great Schism” (schism means “break” or “split”) between the western and eastern churches.

In the wake of iconoclasm, the leaders of the Orthodox church, the patriarchs of Constantinople, would claim that innovations in theology or Christian practice were heresies. This attitude extended to secular learning as well – it was acceptable to study classical literature and even philosophy, but new forms of philosophy and scholarly innovation was regarded as dangerous. The long-term pattern was thus that, while it preserved ancient learning, Byzantine intellectual culture did not lend itself to progress.

The Late Golden Age and the Final Decline

Byzantium’s last period of strength was under a Macedonian dynasty, lasting from 867 – 1056. A murderous leader named Basil I, originating from Macedonia, seized the throne in 867 and initiated a line of ruthless but competent leaders who governed for about two hundred years. Under the Macedonians, Byzantine territorial lines were pushed back to part of Mesopotamia and Armenia in the east and Crete and Cyprus in the Mediterranean. The important effect of these reconquests was trade; once again, Byzantium was at the center of an international trade network stretching across Europe and the Middle East. This vastly enriched Constantinople and its region, leading to a renaissance in building and art. Under the patronage of the Macedonian dynasty, some ancient learning was revived, as scholars tried to find ways to make the work of the ancient Greek masters compatible with Orthodox Christian teachings.

During this late golden age, Constantinople’s population rebounded, with food supplies guaranteed by the imperial government. Even the poor lived better lives in Constantinople than did the relatively well-off in Western Europe, much of which was barbaric by comparison. An elite class of administrators occupied a social position somewhat like the ancient Egyptian scribes and were educated in Christianized versions of Greek learning and classics; one scholar named Photius produced an encyclopedia of ancient Greek writings that is the only record of many texts that would have been otherwise permanently lost.


Byzantium in its late golden age – note that Constantinople remained both geographically and politically central.

These happy times for Byzantium ended when the emperor Basil II died in 1025 with no male heirs. Simultaneously, a series of bad harvests hit the empire. Byzantium’s military success was based on the themes, which were in turn based on the existence of reasonably prosperous independent farmers. Bad harvests saw those farmers vanish, their lands swallowed up by the holdings of wealthy aristocrats. As had happened in the Roman Republic so long ago, the problem was that there were thus no soldiers to recruit, and the armies shrank.

Likewise, the relative calm of the Macedonian period ended with the rise of a new group of invaders from the east: the Seljuk Turks. A powerful group of nomadic raiders from the western part of Central Asia, the Turks had converted to Islam centuries earlier. Despite having no centralized leadership (the Seljuks themselves were just one of the dominant clans with no real authority over most of their fellow raiders), by about the year 1000 CE they began invading both Byzantine territories and those of their fellow Muslims, the Arabs. Over the next few centuries, the Turks grew in power, steadily encroaching on Byzantium’s territories in Anatolia.

Image Citations (Wikimedia Commons):

Eastern and Western Empire Map – Pixeltoo

Justinian Mosaic – Bender235

Map of Constantinople – Cplakidas

Virgin Mary Icon – Public Domain

Late Golden Age – Cplakidas

This chapter has been derived with modifications from Chapter 11: Byzantium in Western Civilization: A Concise History.


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