The Fall of Constantinople

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29 May 1453 – the day Constantinople finally fell – marks the symbolic end of the Roman Empire and, to many modern historians, the transition from the Medieval to the Early Modern Era. The Ottomans’ conquest was far from unexpected: indeed, the collapse of the Eastern Roman (Byzantine) Empire was arguably not just inevitable but long overdue. If anything, the empire’s collapse had already taken place two centuries ago, after the Sack of Constantinople in 1204. The city’s fall was just that – the end of a diminished city-state. However, its significance was deeper than symbolism. The Fall of Constantinople was one of history’s most seminal events: it dramatically shifted the political dynamic in Europe, pitting the Ottoman Empire against the European powers, and bringing about the golden years of the Renaissance and the Age of Discovery.

The Byzantine Empire had incredible longevity. One of the most significant reasons for this, and what made Mehmed the Conqueror’s achievement in 1453 so extraordinary, was the capital’s impregnability. Flanked by three waterways – the Golden Horn on its northern side; the Bosphorus River on the east; and the Sea of Marmara on the south – the city could only be attacked by land on its western front, which was guarded by the extensive stone Theodosian Walls which rendered conventional Medieval besiegement futile. They would not be overcome until a millennium after their construction.

With a fortified capital strategically positioned at the nexus between Europe and Asia and a skilled workforce of engineers developing technological innovations, the Eastern Roman Empire was initially able to thrive under the reign of Justinian I. They reconquered many of the old Western Roman Empire’s territories by the time of his death in 565.

However, the empire’s government would soon face internal issues that would lead to its eventual destruction. The ‘theme’ system of military recruitment required each region (‘theme’) to contribute local troops to the imperial armies. This provided a large, cheap central force and ensured that no one region would become too powerful by stockpiling troops. The system worked effectively in Byzantium’s heyday from 650 to 1025.

In the 8th Century, the Byzantine nobility bought up land owned by peasants, greatly undermining the ‘theme’ system by displacing peasantry and thus making them ineligible to be called up to the army. The system’s gradual collapse from the 11th Century onwards caused the empire’s increased reliance on foreign mercenaries. These armies were both expensive, eventually bankrupting the Byzantine economy, and unreliable, as these foreign troops were easily able to occupy Byzantine lands in times of crisis or when they went unpaid.

By the 11th Century, the Empire was in decline. This was expedited by the catastrophic Byzantine defeat to the Seljuk Turks at the Battle of Manzikert in 1071, resulting in the loss of most of its territory in Anatolia (modern Turkey) – the heartland of the empire which was the major recruiting ground for soldiers. To make matters worse, Emperor Romanos IV Diogenes was captured by the Seljuks during this battle, creating a power vacuum that prompted a ten-year long civil war in which eight separate revolts took place.

The damage of these revolts was compounded by local factions employing Turkish mercenaries, who often turned on the Empire. Most notably, the regions of Ionia, Phrygia, Galatia and Bithynia in western Anatolia were taken by the Turkish soldiers employed by Nikephoros Melissenos, a Byzantine general, in 1080.

The loss of the empire’s last remaining territories in Italy and increased attacks on their Balkan territories around the same time prompted Emperor Alexios I Komnenos to request urgent military support from the West to fend off the Seljuk Turks. The resultant First Crusade, initiated in 1096 after Pope Urban II’s declaration of support for the Byzantine call to arms, bore some fruits in the Levant and Anatolia. However, the Empire would never recover from the preceding decade-long crisis.

It was the Fourth Crusade that finally brought about the capture and ‘Sack of Constantinople’ in 1204, irreversibly damaging the city and briefly destroying the empire. In 1203 the imprisoned former Emperor Alexios IV Angelos fled to the West, promising the leaders of the Fourth Crusade generous payment if they helped him retake the throne. Following the siege of Constantinople, Alexios was crowned Emperor, yet a few months later was deposed and executed amidst mass rioting in the city. When the next Emperor Alexios V refused to pay the Crusaders, the Crusader and Venetian leadership captured, looted and pillaged the city, seizing most of the city’s ancient treasures and 900,000 silver marks, and killing 2000 citizens of Constantinople.

A mass exodus from the city ensued. Much of Constantinople became depopulated and ruinous, and would remain so until its fall, such that, by 1453, the population had shrunk from its peak at 800,000 to merely 50,000. There were even large swathes of abandoned land within the walls used for farming.

The Byzantine nobility that fled after the Sack would go on to found several Byzantine successor states, notably Trebizond along the southern coast of the Black Sea, Nicaea in Bithynia, and Epirus in the northwest of the Greek Peninsula. Nicaea was eventually able to reconquer Constantinople from the Crusader Latin Empire established there after the sack.

Yet more blows were dealt in the 14th Century: the Byzantine civil wars of 1321 – 1328 and 1341 – 1347 destabilised the Empire, depleting its military resources; the Black Death killed nearly half the population; and the Fall of Gallipoli in 1354 to the Ottoman Turks allowed them to cross into Europe and surround Constantinople on all sides. Byzantium’s decline was now inexorable. By 1453, the Eastern Roman Empire consisted merely of the city of Constantinople itself and a few square miles of surrounding countryside.

With the imminent threat of attack from Mehmed II’s forces, Emperor Constantine XI Palaiologos appealed to Pope Nicholas V for military assistance. However, this call was largely ineffective. For one, centuries of enmity existed between the Eastern and Western Churches, so while the Pope did issue a plea for help on their behalf, the West was not particularly inclined to help. Furthermore, the Papacy’s power in the West was waning at this time, so he had no political means to compel the co-operation of the major powers.

Perhaps more important than a lack of willingness to help was an inability to do so. The major powers of Britain, France, Spain and the Holy Roman Empire had all been involved in their own debilitating conflicts shortly before 1453, and so were in too weak a state to send substantial military assistance to Constantinople. France and Britain were still in the throes of the Hundred Years’ War; Spain was near the final stages of the Reconquista (driving the Umayyad Arabs out of the Iberian Peninsula); and Hungary and Poland had just suffered a crucial defeat by the Ottomans at the Battle of Varna in 1444.

As such, little help was forthcoming: Cardinal Isidore arrived with 200 archers; Giovanni Giustiniani, an accomplished Genoese captain, arrived with 700 men; and a small contingent of Venetian ships remained. In total, the Byzantine forces numbered only 7000, of which 2000 were foreigners, compared to the 50–80,000 amassed by the 21-year-old Ottoman Sultan Mehmed II.

The Byzantines hoped to endure the siege until reinforcements could arrive from the West. The key element of their defence involved a chain across the Golden Horn Strait to prevent Turkish ships entering the harbour. If this was successful, the Ottomans could only assault from the west. They trusted that the Theodosian Walls, still some of the world’s strongest fortifications and  recently repaired, could sustain the Ottoman medium-sized cannons to which they were accustomed.

However, the destructive force and range of the Ottoman cannons far exceeded Byzantine expectations. This was largely thanks to the Hungarian inventor Orban (whom the Byzantines nearly employed, but could not afford) building the extraordinary “Basilica”, a large-calibre cannon the size of which has never been seen before, capable of shooting half-tonne cannonballs over a mile. It was so powerful that it often killed some of its operators and lasted only six weeks before becoming defunct.

Sultan Mehmed II’s army arrived on 5 April and the siege began the next day, once the Ottoman cannons were set up along the western wall of Constantinople. With the support of cannon fire, Ottoman raids of the walls began on 7 April, comprised of small groups of Mehmed’s light infantry and skirmishers. These initial assaults were ineffective, and the Byzantines were largely able to repair most of the damage done to the Theodosian Walls by cannon fire since reloading of these cannons took upwards of three hours. Bombardment of the walls began in earnest on 11 April and continued to the end of the siege.

At first, the Turkish fleet, hundreds strong, was unable to reach the Byzantine harbour due to the aforementioned chain, so its ships remained in the Bosphorus, guarding it to prevent any Christian ships from entering or exiting the city. Yet by 28 April, Mehmed had circumvented the chain by constructing a ramp of greased logs across Galata to the north and moving his ships across it from the Bosphorus Strait into the Golden Horn. Constantine XI desperately deployed his fireships to destroy the Ottoman vessels, but to no avail. Henceforth, the Byzantines were forced to allocate a part of their forces to defend the northern wall facing the Golden Horn, which reduced the number of defenders along the main western wall. They were now under enormous pressure.

By mid-May, the Ottoman cannons had already created several breaches in the western wall. However, these breaches were too narrow to send troops through, so the Ottomans resorted to mining tunnels to bypass the Theodosian Walls. Yet the Byzantines were able to dig counter-mines under the command of Johannes Grant, a German engineer who came with the Genoese contingent under Giustiniani, and each Turkish tunnel was intercepted and destroyed with Greek fire.

After three days of preparation, the Ottomans’ final assault came on 29 May and was successful in taking the city. Shortly after midnight, the Ottoman troops made several waves of attacks, focusing on sections of the damaged Blachernae walls in the northwest. When Giovanni Giustiniani was grievously wounded during the last wave of assaults, the predominantly Genoese defenders began to panic and rout, leaving large parts of the wall undefended. The subsequent surge of attacks overwhelmed Constantine’s forces, and when the Turkish flag was seen above the Kerkoporta, the defence collapsed as Greek soldiers abandoned their positions, instead running home to protect their families.

Following the breach of the Theodosian Walls and the mass retreat of the Venetian, Genoese and Greek troops to the harbour, the Ottomans rampaged through the city. Mehmed allowed his troops to loot and pillage the city for three days as they pleased, with the exception of the Hagia Sophia being decreed as off limits. After taking the city of Constantinople, the Sultan Mehmed II earned the moniker of “the Conqueror”, and would go on to move his capital there, consolidating Ottoman control of the region.

For Christendom, his victory was extremely worrying – now without a buffer against the Muslim powers in the East, Europe had to rely on Hungary to halt the Ottomans’ expansion westwards. News of the fall of Constantinople would soon reach the West as fleeing Venetian sailors arrived in Italy. Despite the historical and religious importance of the city, the response was muted.

However, with every dark cloud comes a silver lining. The fleeing Venetian ships carried Greek refugees from Constantinople, bringing with them new artistic techniques to Italy and Western Europe, inspiring the Golden Age of the Italian Renaissance. And with the Bosphorus now firmly in hostile Ottoman hands, Western traders were no longer able to pass through their usual trade routes in the Black Sea, thus prompting a new Age of Discovery, with exploration and conquests that made the Western powers naval empires. As such, the Fall of Constantinople drastically shifted the contemporary power dynamics within Europe and shaped its future, and therefore the world’s, for centuries to come.

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