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One general preserved the Eastern Roman Empire for seven more centuries, crushing the Sassanids and creating a governing system that blunted the spread of Islam.

At the dawn of the seventh century, what remained of the Eastern Roman Empire (and the fate of Western civilization) was threatened on all sides. The seat of empire had long since been moved from indefensible, invasion-ravaged Rome to Constantinople. Between 536 and 552, Rome itself had changed hands between the Goths and the empire no fewer than five times. Although Emperor Justinian, a Macedonian, had expanded the Eastern Empire considerably in his rule from 527–565, now many Lombards were pushing into Italy, Avars and Slavs were invading the Balkans, while Persians (the Sassanid Empire) were threatening from the east—and Arabs, not yet a danger, were organizing to the south.

The army struggled to maintain the empire’s boundaries, without strong government support. The reigning emperor, Phocas, who had usurped the throne in 602 at the head of a rebel army he had raised along the Danube River, was proving to be a murderous incompetent. His was the first violent overthrow of government since Constantine had chosen Constantinople as the new capital of the Roman Empire. The Justinian dynasty that Phocas overthrew had ruled since 518, and its few survivors did not welcome their new leader. On entering Constantinople, he had slaughtered all opposition, which included most of the people who knew how to run the government.

Citizens of the empire, who called themselves Romans but who have been known since the eighteenth century as Byzantines, were in desperate need of a strong, competent leader. They found such a man in the farthest reaches of the empire, in North Africa. He was a soldier named for the mythical Greco-Roman hero, Hercules. Heraclius was called to Constantinople by those who despised Phocas.

He would have to deal with serious internal and external threats to the empire. The Eastern Romans had been weakened by chronic economic depression. In Constantinople impassioned mobs battled in the streets. Elsewhere in the empire, rioting raged from the great Egyptian metropolis of Alexandria to Beirut in Lebanon, and Antioch on the Syrian coast.

The plague returned. Since first bursting up from Egypt in 541, this savage pestilence—possibly the bubonic plague—had made the rounds of the Mediterranean ports, spread inland, and killed perhaps one-third of the population of the empire.

A different threat loomed from Persia. Byzantine Emperor Maurice had placed King Khosroes II on the Sassanid throne in 591. Now, with the usurpation by Phocas, Khosroes saw an opportunity and he prepared for war with the Byzantines, in the name of a man in his court who claimed to be the son of Maurice, and so a legitimate heir to the Roman Empire. When Phocas responded by pulling all his troops out of the Balkans, the Asiatic Avars and their Slavic subjects began raiding the Eastern Empire as far south as Athens, unopposed.

In the East, the Persians routed the first Imperial Byzantine forces sent against them. Then they took Armenia, crossed the Tigris River, and swept through Cappadocia, in what is now central Turkey. In 607 neighboring Galatia fell, and Paphlagonia. Now Persia controlled Roman territory reaching to the Black Sea.

Then Khosroes turned his attentions south, to the rich merchant cities of the Levant, riotous, plague-ridden, and hostile to the high-taxing court in Constantinople. In these ancient Hellenic port cities, Orthodox Christians had battled Jews and heretics for years. The Jews in Antioch revolted in 608, took over the city, repulsed the forces of Phocas, and struck a deal with Khosroes. The Byzantine Empire was shrinking like a puddle in the sun.

Meanwhile, in Constantinople, a mob set fire to the government building that housed the jail and set the prisoners free. Reeling from the Persian assaults in the east, giving ground in the north, and facing revolt in the capital and most parts of the Byzantine realm, Constantinople’s citizens must have thought their empire was near its end.

In the midst of this collapse, the chief officer of the emperor’s own guards wrote secretly to Africa, the most distant province of the empire, begging for help from the exarch (governor) of the province that is now Tunisia. There the aging governor, father of Heraclius, had received his posting as a reward for serving the empire as a successful general under Emperor Maurice, the leader Phocas had usurped. He was not African and had only been in Carthage for 10 years. He was likely of Armenian descent, as were so many other prominent Eastern Romans.

The exarch had served with distinction in a campaign against the Persians along the Euphrates River before coming to Africa, and he still had strong connections in the area now being overrun by the Persians. Although he was too elderly to undertake a campaign, his son, Heraclius, was thirty-five, a prime age to save the world. Still, in taking any action against Phocas, Heraclius and his family risked far more than status and position: failure meant death.

It is tempting to see Heraclius as driving the revolt from the beginning, but he made his first moves in his father’s name. Tall, brawny, golden-haired, and energetic, Heraclius had allegedly fought lions as well as Berbers in the mountains of Africa. There was something of Hercules in his personality as well as in his name.

His first act was not to proclaim himself emperor but to issue a coin showing himself and his father, the exarch, as consuls of Rome—the ancient, traditional Roman rulers. The office had lapsed in Africa, but consuls remained powerfully evocative to a people who believed they were carrying on the heritage of Julius Caesar, who had died some 650 years earlier. Roman Africa was still steeped in a Latinate, classical culture, as if nothing had changed since the days when Rome flourished.

After proclaiming that he was restoring the true, traditional order that Phocas had swept aside, Heraclius set his plans in motion. He sent one army by land to Egypt under the command of his cousin, Niketas, to confront General Bonosus, who commanded almost the entire army of Phocas. His goal was to secure the richest prize of the East—Egypt accounted for thirty percent of the revenues of Constantinople and supplied the capital with grain. To counter, Bonosus tried to intimidate the eastern sections of the empire but only aroused hatred. Then, after a fierce struggle, his troops lost to Niketas.

Meanwhile, Heraclius himself proceeded by sea across the Mediterranean with an imperial army of Berber and Mauritanian mercenaries. They stopped at Sicily and Crete, lining up support along the way. Although Phocas had plenty of warning, he had lost control of everything but his torture chambers, so Heraclius reached Constantinople almost without opposition.

The general who was supposed to defend the city pretended to be sick. The elite imperial guard commanded by Phocas’ own son-in-law welcomed Heraclius and pledged allegiance to him. Rioters filled the streets. A mob seized the city prefect of Constantinople, a position equivalent to the mayor, and burned him to death in a public forum.

Not one soldier stood for Phocas. An officer he had personally offended took the emperor prisoner and delivered him by boat to Heraclius, still aboard his own ship in the Sea of Marmara.

Heraclius killed the prisoner with his own hand, beheaded him, and ordered dismembered pieces of his body displayed in public areas of the city. Some prominent Byzantine aristocrats had already visited Heraclius, to arrange his succession. Without opposition, Heraclius then entered the city and was crowned emperor of Rome by Sergius I, patriarch of the Christian church, in October 610.

At the time, this did not look like a great prize. The realm was in tatters. Indeed, Heraclius may not have known how extreme the situation was when he took on the job. He found the treasury was bankrupt. Yet, the greatest immediate threat was continued pressure from the Sassanid Persians. Ignoring the crowning of a new Roman emperor, Khosroes continued to insist his anti-imperial actions were designed to enthrone a son of Maurice.

In 613 a Persian army threatened Antioch, and Heraclius, hastening to its defense, was soundly trounced. The fabled ancient Hellenic city fell to the Persians, probably to the relief of many of its inhabitants, especially the Jews, who had been persecuted under the Byzantine Christians.

With the loss of Antioch, the empire had been cut in two. Now the only connection between Constantinople and Egypt, a vital source of food and funds, was the still-powerful Roman navy. Later that year, Damascus also fell. Other cities began making their own deals with the invaders, as if the empire were inconsequential. Another Persian victory over the Roman armies in Syria allegedly inspired a verse in the Koran, although neither Heraclius nor many in his empire had heard of Mohammed, then a little-known mystic in Mecca, far to the southeast.

By this time, Heraclius had few troops, fewer officers, and little money to recruit and pay men and officers to keep the Persians from overrunning the Levant. Nevertheless, he managed to assemble an army and battled the Persian general Shahrbaraz to a bloody tie near modern Homs. However, the brutal death toll was more damaging to the depleted Romans than to the Persians. To protect his troops, the emperor had to limp back to Constantinople while Shahrbaraz wintered in the Holy Land, rebuilding. In 614 the Persian army stormed and captured Jerusalem, slaughtering thousands, possibly aided by the resident Jewish population. Shahrbaraz not only enslaved the survivors and took them—and the patriarch—back to Persia but also damaged the Church of the Holy Sepulcher and carried off Jerusalem’s own piece of the True Cross, the most venerated of all Christian icons.

Refugees from the fighting flooded south into Egypt, many of them Jews and heterodox Christians, people marginalized by the increasing pressure from Constantinople for religious conformity. Arab tribes had already begun raiding into the area east of the Dead Sea, while the rampaging Persian armies to the north and west kept Constantinople busy, allowing the tribes to raid with relative impunity. At the end of the decade, Shahrbaraz and his army entered Egypt, and another Persian army raided through Anatolia as far as Chalcedon, across the Bosporus from Constantinople. The Eastern Roman Empire looked increasingly vulnerable.

Twice Heraclius appealed to Khosroes for peace, but the shah rejected his overtures. Shah Khosroes may have intended to restore the ancient empire of Xerxes and Darius. Whatever his intentions, he had little reason to make peace when his armies were dominating every Byzantine force they attacked.

The shah himself did not even campaign. He stayed in the safety of his luxurious Persian palaces, where he kept lavish hunting parks stocked with exotic game. At one point, he informed Heraclius he would consider peace only if the emperor renounced Christianity and converted to Zoroastrianism, the religion of Persia.

For a time in 618, Heraclius considered moving his capital to North Africa, a more secure and defendable position. Reportedly, Patriarch Sergius I dissuaded him. Instead, the emperor cut expenses by canceling the dole in Constantinople. A return of the plague further reduced the population.

Every season brought a new crisis. Next, Egyptian Alexandria, second city of the empire, fell to the Persians. In the Balkans, the Avars took Nis, birthplace of Constantine I, founder of the Eastern Roman Empire. The Slavs were penetrating into the Greek heartland, as far south as the Peloponnesus, and Croats and Serbs were pushing into Dalmatia, along the Adriatic.

Heraclius, now 45, found no respite even at home. His first, beloved wife Eudokia had died, leaving him an infant son and daughter. Seeking comfort, he married his niece, Martina, although the charge of incest caused great public outcry. Patriarch Sergius I had demanded that Heraclius not marry her; after the wedding, he called on the emperor to renounce and leave her, but Heraclius refused. Martina proved a constant companion, traveling with him on his campaigns, and bearing him ten children.

Needing cash, Heraclius demanded and was given the wealth of the churches, even melting down the candelabras of Emperor Justinian’s glorious cathedral, Hagia Sophia, to mint gold and silver coins. Perhaps to justify this outrage against religion, he began wearing a cross, and called on his army to protect Christians from the fire-worshipping Zoroastrian Persians.

He also called in the wealth of the provinces, both to field an army and to buy time from the Avars. For ample money and in exchange for distinguished hostages from the Byzantine court, Heraclius persuaded the Avars to cease their raids, so he might concentrate on the Persian threat.

He spent Easter of 621 in Constantinople, celebrating the resurrection of Christ. The next day, he left the city in the care of the patriarch Sergius and established his headquarters in Trebizond, in Anatolia, intending to lead a military campaign with no less a goal than to resurrect the Roman Empire.

Heraclius had spent several years laying the groundwork for this campaign, installing a system initially designed by Emperor Maurice in Ravenna and put into place by his own father in Africa. It was intended not only to create an army and win this war but to create a foundation for the continued survival of the Roman Empire.

Lacking wealth to pay his soldiers, he appointed military governors to rule the lands in his kingdom. In exchange for giving the governors broad control over their lands, the emperor received their military service and the expectation that they would bring with them a reliable supply of trained soldiers. From Trebizond, he built up alliances with Armenians and Georgians, and formed an accord with the Khazars, who dominated the steppes between the Black Sea and the Caspian Sea.

The Romans had already been fighting the Persians for centuries, and they had the book on them— literally. The Strategikon, probably created at the direction of Emperor Maurice, explains in detail how to fight Persian armies: how the Persians avoided open plains where massed lancers could come at them in unbroken lines, how they failed to secure their flanks, and how their night camps were often disorganized and poorly guarded. Heraclius relied heavily on the advice in this book in his campaign against the Persians. He knew what he had to do; his main challenge was creating an army that could carry out his plans.

The Roman navy still dominated the Mediterranean, so Heraclius could sail without hindrance around Asia Minor. Where Anatolia meets the Levantine coast, a little plain channels land travelers between two formidable mountain ranges. Armies had contested this plain for millennia. Alexander the Great had beaten the Persian king Darius at the nearby city of Issus. This was where Heraclius chose to begin his campaign.

Heraclius assembled his troops there, gathered local militias, and hired mercenaries. Not having trained legions, he had to spend time teaching them to be soldiers and coordinating tactics. Many of his mercenaries were probably Arabs, Palestinians, and Bedouins. He personally lined them up and drilled them. Giving his troops mock weapons of wood, he divided them into two bands and had them fight each other, so they could gain the experience of battle without significant risk.

Above all, he harangued his troops, reminding them of what they had been suffering at the hands of the Persians, how their maidens had been ravished, and their elders murdered. He pledged that he would struggle in front of them all, until death. In fact, his personal bravery would inspire his soldiers, and his quick decisions and daring and aggressive maneuvers positioned them to win battles.

The Persian general, Shahrbaraz, marched his army up from Egypt to confront the new force. Heraclius maneuvered around him for a few weeks, and then attacked him with the rising sun behind his forces, so that the light blazed into the Persians’ eyes. The orderly, disciplined troops of Heraclius easily smashed the disoriented Persians, and Shahrbaraz fled, leaving the field to the emperor.

It was an encouraging victory, and holding this crossroads was vital to holding the Levant, but Heraclius was forced to return to Constantinople almost immediately after his triumph. Although he had negotiated a truce with the Avars before attacking the Persians, they were raiding Thrace, and he dared not leave them unopposed.

The Byzantines had three proven techniques for dealing with enemies. Over the centuries, rulers had always favored diplomacy, while getting somebody else to do their fighting. Now the Avar khagan (prince) offered Constantinople a truce, which Heraclius eagerly accepted. He planned a lavish theatrical event on the Thracian Plain to formalize the pact and celebrate it.

However, the Avar leader had set up an ambush. Heraclius managed to flee away with his crown tucked under his arm and his royal purple cloak flung away so that no one would know who he was.

The Avars followed, but the Theodosian Walls of Constantinople stopped them. These formidable defenses stretched from the Sea of Marmara across the peninsula to the Golden Horn, blocking the only land approaches to the city. After a few futile assaults, the Avar horde agreed to another uneasy truce, for which Heraclius paid an enormous sum. Now he could turn his attention again to Persia. In 624, taking his wife and some of his children with him, Heraclius left Constantinople for the four-year campaign that would determine the fate of the Roman Empire (and Western civilization).

Between Anatolia and the Iranian plateau lies Mesopotamia, a land dependent on its two great rivers, the Tigris and Euphrates; to the north are the mountain lands of Armenia and Georgia, a natural boundary. Khosroes’s armies had swept across these lands into the Byzantine Empire during the rule of Phocas. Now Heraclius planned a daring attack at the heart of the Sassanian Empire—even as the Persian shah’s armies ravaged sections of his own lands. This time, he marched through Anatolia, gathering up many of the troops he had trained in the Levant, and then headed north and east into Armenia.

Once again he offered Khosroes peace. In response he got a letter that began, “Khosroes, honored among the gods, lord and king of all the earth, offspring of the great Aramazd, to Heraclius, our senseless and insignificant servant.” The shah saw no reason to negotiate; he was winning.

In Armenia, Heraclius was close to the Caucasus, heights harboring traditional enemies of the Persians, mostly Western Turks. Making allies of these warriors, Heraclius struck south and east toward the Sassanian Persian capital, Ctesiphon.

Khosroes countered by ordering Shahrbaraz, the general who had taken Jerusalem and Egypt, to lead his army into Anatolia, to block Heraclius if he tried to return to Constantinople, and to cut off his supply route. Shahrbaraz was to hold the mountain passes and to put pressure on Constantinople itself.

Two additional Persian armies set out to smash Heraclius as he came down through the mountains from Armenia. Their goal was to drive him back toward Shahrbaraz, so the three armies could converge and crush the Byzantine force.

Heraclius was ready for this threat. In the rough country north of Mesopotamia, knowledge of the terrain was essential, and his new allies supplied accurate intelligence. While Khosroes’s advancing generals struggled to coordinate and catch their enemy between them, Heraclius maneuvered around them, picking off their guards and launching raids at their flanks. When the two Persian generals finally thought they had him pinned down, Heraclius took off on a daring night march. Then he confronted them on level, grassy ground—terrain that suited his soldiers but not his opponents.

The opposing forces faced each other for a day but did not engage. The next day Heraclius marched off again, going south toward Persia, burning villages and fire temples as he went. The Zoroastrian temples were typically dome-shaped structures over an eternal flame. By destroying the centers of the Persians’ religion, Heraclius incited his opponents to take a risk they might otherwise have shunned. The Persian armies attempted to circle around him, but they blundered into the marshlands at the headwaters of the Euphrates and got lost.

By the time they had regrouped, it was nearly winter. The Persian generals took their armies into winter camp, and Heraclius set up his own winter camp deep in enemy territory. Halfway through the winter, he led a daring and risky attack on the nearest Persian army and, catching the troops unawares, slaughtered many officers as well as soldiers. They even captured one general’s wives, personal arms, his gold shield, sword, and spear. The general himself escaped only by leaping naked onto his horse and galloping off. With the rations he captured that day, Heraclius spent the rest of the winter in secure quarters, with plenty to eat.

Yet, he did not feel he could keep driving into the Persian heartland. Behind him there was still that formidable enemy, General Shahrbaraz, controlling western Anatolia. In the spring, the emperor turned his army toward the west, reaching the coast near Issus again, and then marched across Asia Minor to the northeast, to the Black Sea at Trebizond, moving east of where Shahrbaraz and his forces were positioned. Fortifying passes as he went, Heraclius reestablished Byzantine control wherever possible.

From the comfort of his palace, Khosroes ordered a counterattack. He demanded that Shahrbaraz strike at Constantinople itself. In practical terms, this meant laying siege to Chalcedon, on the Asian side of the Bosporus, until the Persians could find a way to cross the mile of turbulent water separating them from the Byzantine capital. At the same time, the shah made a pact with the Avar khagan, who agreed to attack the Byzantines in their European lands.

In the summer of 626, the Avars mounted a furious assault, bringing siege towers and catapults to bear against the great walls raised by the Roman Emperor Theodosius. Constantinople’s residents battled them hand to hand at the gates, flung down their siege ladders, and the great walls held. Heraclius knew of the attacks but stayed in Trebizond, sending only a contingent to help lift the siege while local commanders led the defense.

The primarily civilian defense succeeded, in part because the Christian Byzantines strongly believed that God would not let them lose, or at least the Virgin Mary would not. Her image in the Blachernae district’s Church of Panagia of Blachernae was thought to be the city’s palladium. Even the Avar khagan allegedly saw “a woman alone, in decorous dress, hurrying around on the wall,” leading the resistance. The high and thick defensive walls and the public’s belief in providence stymied the khagan’s forces. The populace repulsed his bloody assaults, and the siege wore on.

Meanwhile, Shahrbaraz could not support the Avars. The Byzantine navy kept his army on the Asian side of the Bosporus, although the Persians battered Chalcedon and burned at least part of it. In August the Avar khagan retreated, as his soldiers had grown restive, angry, and probably sick, and Shahrbaraz broke off his own siege.

Furious that his plans had failed, Khosroes sent a secret messenger to a high-ranking officer on the staff of Shahrbaraz, ordering him to murder the general. At least that was the message Heraclius claimed to have intercepted when he forwarded it to the Persians’ leading general. Whether the letter was purloined or forged, that message and another ordering the execution of four hundred Persian officers effectively neutralized Shahrbaraz and his entire army for the remainder of the campaign.

Now the emperor was free to attack the heart of Persia. In the fall of 627, he went east, to the Caucasus, and again gathered his allies; his army may have numbered as many as fifty thousand soldiers by this time. He plunged down into Persia, toward Ctesiphon, the capital, looting and burning as he went.

Khosroes dispatched an army to intercept him, but Heraclius, moving more quickly than expected, got his army between the Persians and their capital. He devastated the country as he went, so the Persians following him were unable to forage for sustenance. The emperor crossed the Greater Zab River and camped near storied Nineveh. The Persians pursued, expecting help from the shah, but Heraclius maneuvered to bring them to battle before that help came.

At dawn on December 1, 627, the two armies clashed. Heraclius himself led his men into battle. In hand-to-hand fighting, he killed several Persians including General Rhazates as his men slaughtered the exhausted and famished enemy. In eleven hours of fighting, they also killed most Persian officers. The following day, what remained of the shah’s army melted away into the mountains.

Heraclius marched south, toward the Lesser Zab, sending an advance guard to seize the bridges. The Persian army he had defeated at Nineveh regrouped as best it could, linked up with its reinforcements, and trudged ineffectively after him.

Late that year, the Byzantines crossed the Lesser Zab. Heraclius had reached the Persian heartland. He burned two of Khosroes’ palaces and made camp at a third, where he held horse races to entertain his army. At this palace, they also found herds of antelope and wild asses, fattened for the shah’s hunting pleasure, and an abundance of other supplies. After the quick march and the hard fight, Heraclius rewarded his men with what amounted to a luxury vacation.

Khosroes was in a panic. He fled his palace of Dastagerd, making for Ctesiphon, although an old prophecy had warned him he would meet his end there, and he had avoided that city for twenty-four years. Heraclius, tipped off, moved on Dastagerd and took it with no resistance.

Once again, the victorious army found rich treasure and abundant supplies, and Heraclius treated them to a “celebration of lights.” What does this mean? This might have been a torchlight parade or perhaps fireworks of some kind, and Iran is famed as the Land of Fire, where flames erupt from the ground. Whatever it was, it signaled the glory of a rising Byzantine Empire.

The Persians’ empire was crumbling. Having reached Ctesiphon, Khosroes dared not enter, fearing the prophecy, and the shah fled farther west, leaving some of his wives and children behind. After this cowardice, his own sons rebelled and made peace overtures to Heraclius. One son captured Khosroes, tormented him viciously, and killed him. In the peace that followed, the Persians returned all the lands and cities they had taken from the Byzantine Empire, including Jerusalem, its patriarch, and the piece of the True Cross.

Heraclius had brought the great, thousand-year-old Persian Empire to its knees. Persia never recovered its glory. Each short-lived new shah was soon overthrown, either by an envious brother or a scheming general. With each shakeup, the country would fall further into disintegration. Soon it was beset and conquered by the same unexpected enemy that would threaten the Byzantines.

Heraclius had restored the East to the Roman Empire, not only in governance with occupying armies but also in spirit. He was at the height of his power, a worthy successor to Justinian, in the spring of 631, when he entered Jerusalem on foot, restored the rescued patriarch to his churchly throne, and returned “the precious and life-giving wood” of the True Cross to its shrine.

Had he not stepped in and restructured when he did, the eastern gateway to Europe would have stood open. In restoring the army, arranging it by “themes” or territories, Heraclius made sure that each soldier found support from his own land. This meant that raising an army placed less burden on the imperial treasury. In turn, the expectation of military service meant that soldiers could be raised when needed.

By restoring an aura of authority and action, Heraclius renewed the power of the office of emperor, power his inept predecessors had endangered. That authority kept the citizens of the empire faithful to the imperial will for hundreds of years.

Heraclius switched the Byzantines’ official language from Latin to Greek. The Eastern Roman Empire was, after all, Alexander’s empire as well as the creation of Augustus Caesar and Constantine. The change of language underscored a change of leadership and the remaining empire’s Eastern emphasis. Heraclius founded the modern Byzantine Empire by merging the Greek and Latin traditions together in a confederation that would stand as Europe’s bulwark against Islam for centuries.

Yet, within a few years of his victory at Nineveh, everything he had accomplished seemed swept away. Beset with illness, Heraclius sank also into mental confusion. An enemy he had never foreseen thundered out of Arabia, using against him some of the same troops he had hired as mercenaries, men he had helped to train and equip. The prophet Muhammad was dead but the religious wars he had inspired engulfed the Middle East.

Under the Caliph Umar, a trusted adviser of Muhammad, Muslims conquered Syria, Lebanon, and Persia. Heraclius abandoned Syria in 634, transferring the Holy Cross from Jerusalem to Constantinople. Muslims captured Jerusalem in the spring of 638, and then flooded across Egypt and Africa. When Heraclius died in 641, no trace of his conquests from the Persians remained. By 674, Arabs would be besieging Constantinople itself.

The city nonetheless held, and the empire recovered and expanded again, in good part because of the reorganization Heraclius had imposed.

The durability of the government Heraclius founded is remarkable, given the pressures it faced. The Arabs utterly swept aside the Persians, weakened by the chronic civil wars after Heraclius defeated them. Muslims conquered lands across northern Africa, devastated the Visigoths in Spain, and overran Sicily. However, another seven centuries passed before the Muslim Ottomans finally conquered Constantinople in 1453.

A cornerstone of the strategy Heraclius followed during his long military career was trading land, when necessary, to preserve his army. When he sensed the possibility of losing a battle, he drew back, avoiding a desperate showdown and saving his forces to fight another day. Pursuing as he retreated, his enemies lengthened their supply lines and depleted their ranks, having to leave troops behind to protect an extended rear echelon.

Of all the decisions Heraclius made, none was more important than his choice not to move the capital to North Africa. Constantinople proved to be an incomparable strongpoint. Strategically, it placed the defenders of Christendom and of Greco-Roman culture at the intersection of vital land and water routes.

Like a cork keeping wine in a bottle, the city blocked the eastern invasion route to Europe. Had the surging armies of the caliphs popped the cork, burst into Thrace, and crossed the plains of the Danube at the same time they overran Spain and penetrated deep into France, we could, as historian Edward Gibbon was the first to say, be hearing the call to prayer echo five times each day from the spires of Oxford. Instead, much of Europe remained Christian, and we can credit that to a golden-haired Hercules who became an emperor at the very time the Byzantines needed a savior.


Originally published in the Autumn 2008 issue of Military History Quarterly. To subscribe, click here