The Byzantine emperor occupied a special place among the rulers of medieval Europe. He was commander-in-chief of the imperial army and head of the government. Yet, the emperor was not an ordinary ruler, but God’s Vicegerent on Earth, a deeply pious monarch whose task was to protect and spread Orthodox Christianity. Thus, the emperor’s decisions were felt not only within the Empire’s borders but far beyond.
He was also the heir of none other than the first Roman emperor, Augustus. It may be surprising to some, but “Byzantine” is a relatively modern term, invented in the 16th century when the Empire was no more. During its existence, however, its inhabitants, the Rhomaoi (Romans), called it the Basilea ton Rhomaion or the Empire of the Romans. In the Empire’s long history, many men ascended the throne in Constantinople. However, only a few managed to achieve greatness, to reshape the Empire, and to leave their mark on history.
1. Justinian: The Byzantine Emperor Who Reconquered the West
Justinian I, also known as Justinian the Great, was probably the most important Byzantine emperor. Justinian was born in Tauresium (near modern-day Skopje, Macedonia) around 482, only a few years after the fall of Rome. Justinian’s meteoric rise was greatly helped by his uncle Justin, a distinguished military commander and imperial guardsman, who became the emperor in 518. He quickly promoted Justinian to important positions, preparing him for the throne. Then, in 527, Justin I adopted his nephew and made Justinian his co-emperor. Within four months, Justin was dead, and Justinian I was the sole ruler of the Roman Empire.
Or was he? While Justinian had the final say in the Empire’s affairs, his wife Theodora ruled with her husband as an equal. In fact, Theodora soon became Justinian’s closest advisor, and on more than one occasion, it was her who directed the course of the state — and probably saved her husband’s life. During the infamous Nika Riot in 532, Theodora was the one who prevented Justinian from fleeing the capital and losing his throne. The empress also played a crucial role in shaping the religious policy, helping her husband to bring together the two opposing factions, and strengthen religious unity, one of the main pillars of the powerful Christian state.
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To further bolster the Empire’s efficiency, Justinian sponsored a codification of the Roman law known as Corpus Juris Civilis. Following the revolt that damaged most of the capital, Justinian used the opportunity to embark on an ambitious building program in Constantinople. His most famous monument is undoubtedly the Hagia Sophia, a grand imperial cathedral, and until the Renaissance, the largest domed building in the world.
However, Justinian’s crowning achievement was the reconquest of the Roman West. After making peace with Empire’s traditional rival Persia, Justinian dispatched his most capable general — Belisarius — on an ambitious campaign to restore the lost imperial territories. However, what began as a spectacular success, leading to the reconquest of Vandal Africa, turned into a protracted war that ruined Italy. The situation worsened after an outbreak of the plague (often called the Plague of Justinian), which weakened the imperial military, and the economy. Yet, in the end, the imperial forces triumphed, restoring control over Italy in 562. The emperor in Constantinople once again had control over the entire Mediterranean, from Spain to Syria, Northern Italy to Egypt.
Justinian managed to achieve his plans and restore imperial glory, but at a terrible cost. When he died in 565, he left his successors an overstretched and impoverished Empire, surrounded by enemies, waiting to strike.
2. Heraclius: Triumph and Tragedy
In 610, when Heraclius became emperor, the Empire was fighting for its very survival. Sassanid armies had crossed the eastern border and advanced into imperial territory. In the West, the Lombards were pushing into Italy. Even the capital — Constantinople — was under threat. The Danubian frontier had fallen, leaving the Avar and Slav tribes in control of the Balkans. The Empire desperately needed a hero. Fortunately, Heraclius was the right man for the job.
After executing Phocas, his incompetent predecessor and a man who cooked up the whole mess, Heraclius began consolidating the meager resources at his disposal. With the backing of the patriarch of Constantinople, the emperor melted down Church treasures, raising the crucial funds to continue waging war. But, despite his best efforts, Heraclius could not stop the enemy. In the decades that followed, the Persians conquered all of the Empire’s eastern possessions, including Egypt. Then, in 626, Constantinople itself came under siege, with the Persians on one side, Avars, and Slavs on the other. Heraclius, however, was not among the defenders.
The fate of the capital (and the Empire) hung by a thread, but the emperor and the bulk of the imperial army were thousands of miles away, waging war on Persian home turf. Not since the exploits of Emperor Aurelian had an emperor taken the fate of the realm into his own hands. Heraclius’ gamble paid off. Constantinople survived, thanks to its impregnable walls and mighty navy. A year later, in 627, Heraclius defeated the Persian army at the Battle of Nineveh. Confronted with a powerful enemy at their very doorstep, the Sassanids overthrew their ruler and sued for peace. After 400 years of rivalry and intermittent warfare, the Romans utterly defeated their greatest rival. To make the victory complete, in 629, Heraclius returned the relic of the True Cross to Jerusalem in a majestic ceremony.
However, it did not take long for Heraclius’ triumph to turn into tragedy. The emperor’s marriage to his niece angered the Church, while his attempt to mend a religious schism alienated both factions. Yet, the emperor’s failures at home were incomparable to the calamity brewing in the East — the arrival of the armies of the Arabs.
While the Empire avoided Persia’s fate and managed to survive, a defeat at Yarmouk in 636 resulted in the total collapse of the imperial defenses in the East. Heraclius could only watch helplessly as the territories he fought so hard to secure fell like dominos to the Arab invaders. Five years after Yarmouk, Syria was lost, along with most of Egypt. Plagued by poor health, Heraclius died in 641, leaving the throne to his sons.
Heraclius led his imperiled Empire to one of its greatest triumphs, only to see it become a tragedy. However, Heraclius’ reforms, and reorganization of the army, gave his successors a fighting chance, and the Roman Empire gradually transformed into a smaller but still powerful medieval state.
3. Basil II: The Medieval Roman Empire at its Apex
Born in 958, Basil II was a member of the renowned Macedonian dynasty, which restored imperial fortunes, making the Byzantine Empire the most powerful state in the medieval Mediterranean. However, although he was porphyrogennetos (born in the purple), Basil had to wait for his place in the sun. Basil was only five years old at the moment of his father’s death. Thus the throne went first to the generals Nikephoros II Phokas and John I Tzimisces. Finally, in 976, Basil became Byzantine emperor. For most of his 50-years-long reign, Basil relentlessly campaigned against numerous enemies of the Empire, becoming a true soldier emperor.
First, the new ruler had to confront an open rebellion led by influential military leaders Bardas Skleros and Bardas Phokas. Basil crushed the revolt with the help of the 6,000 Rus, elite warriors who became the core of the famous Varangian guard. Then, the imperial forces moved against the Fatimid Caliphate in the East. After several setbacks against the Fatimids, Basil took personal command in 995 and turned the tide, extending the Empire’s control into Syria and Mesopotamia.
However, Basil’s most significant military achievement was the complete subjugation of the powerful Bulgarian Empire. For several decades, Basil fought a costly war against this stubborn enemy. Finally, after peace was concluded with the Fatimids in 1000, Basil could redouble his efforts and erase Bulgaria from the map. In 1014, the imperial army won a decisive victory at the Battle of Kleidon. For the first time since the 7th century, the Danube frontier was under imperial control, together with the entire Balkan peninsula.
The victory at Kleidion gave Basil II his infamous moniker Boulgaroktonos (the Bulgar Slayer). According to Byzantine historians, Basil took vengeance on hapless prisoners from the battle. For every 100 prisoners, 99 were blinded, and one was left with a single eye to lead them back to the Bulgarian leader, tsar Samuil. Upon seeing his mutilated men, the Bulgar leader died on the spot. Although this makes for a juicy story, it is probably a later invention used in imperial propaganda to highlight Basil’s martial exploits over the weaknesses of his successors.
During his long reign, the medieval Roman Empire reached its apogee. Basil II stabilized and expanded the Empire’s frontiers, erased troublesome Bulgaria from the map, and restored the Danubian frontier. But unfortunately, he left no heir. After Basil died in 1025, his work was quickly undone by his weak and incompetent successors.
4. Alexios I Komnenos: The Byzantine Emperor and a Founder of the Last Great Imperial Dynasty
The Byzantine Empire was like a phoenix. Every time it came to the brink of collapse, a hero would appear to defeat its foes and rebuild the Empire from the ashes. Alexios I Komnenos (also spelled Alexius Comnenus) was one such emperor. Born in 1057 to a wealthy landowning family, Alexios spent his youth in the military, a witness to the imperial crisis. He observed how Basil II’s successors ruined the Empire’s wealth and military might, allowing the enemy to advance deep into Byzantine territory, practically unopposed. In 1081, Alexios seized the throne from his incompetent predecessor and embarked on a mission to save the Empire from imminent ruin. In the process, Alexios founded the last great imperial house — the Komnenian Dynasty.
To say that Alexios faced a difficult challenge would be an understatement. By 1081, the Empire was under siege. Its heartlands in Anatolia had been lost to the Seljuk Turks. In the West, the Normans expelled the Byzantines from Sicily and Southern Italy and threatened the Empire’s positions in the Balkans and Greece. Unsurprisingly, Alexios’ initial counteroffensive failed. In 1081, the Normans of Robert Guiscard dealt a heavy blow to the imperial army in the Battle of Dyracchium. The emperor, however, did not give up. Alexios made a deal with the Holy Roman Emperor Henry IV, and the united Byzantine and German forces to defeat the Normans. Alexios also restored the Danubian frontier by defeating the Pechenegs.
With the Balkans secured, Alexios could focus on recovering vital lands in Anatolia occupied by the Seljuks. Well aware that his own forces were inadequate for the task, the emperor appealed to the West for help. Alexios expected several contingents of elite knights. But the Pope exploited the opportunity and called for a Crusade to liberate the Holy Land. Alexios made the most of this troubling situation, regaining some lost territories with help of the Crusaders, including Nicaea and much of the Anatolian coastline. The emperor continued to wage war against the Seljuks until he died in 1118. Alexios I Komnenos left behind a strong Empire, full coffers, and a formidable army.
The Komnenian emperors continued to bolster imperial power, presiding over a last golden age of Byzantium, known as the Komnenian restoration. Both John II and Manuel I Komnenos expanded the Empire, regaining the territories in the East and the West. Yet, by doing so, they overstretched their limited resources. In addition, the lack of competent rulers following Manuel’s death led to a gradual and fatal decline of the Empire. Andronikos I Komnenos, who ascended the throne after murdering his nephew Alexios II, angered the West after he ordered the massacre of Constantinople’s Latin inhabitants. The deeply unpopular emperor, Andronikos suffered a gruesome end, torn to death by an angry mob on the streets of Constantinople.
Andronikos’ demise in 1185 brought to a sudden end to the Komnenian dynasty. A decade and a half later, Alexios I Komnenos’ legacy crumbled to pieces after the armies of the Fourth Crusade conquered and sacked Constantinople in 1204. From then onwards, the Empire was only a shadow of its former self, awaiting its slow, lingering death. Yet, while Constantinople fell in 1453, and the last Byzantine emperor — Constantine XI — perished in battle, the Byzantine legacy (and by extension, the legacy of the Roman empire) outlived the Empire, influencing the art, culture, and religion of Europe.