Date: February–May 1453.
Location: on the Sea of Marmara, modern Istanbul.
Turkish: 80,000 men. Commander: Sultan Mohammed II.
Byzantine: less than 10,000 men. Commander: Emperor Constantine XI Paleologus.
Constantine the Great established the city of Constantinople as his capital in 323. He occupied the former city of Byzantium, which for centuries controlled the straits separating Asia and Europe. It lies on the Sea of Marmara, flanked to northeast by the Bosphorus and to the southwest by the Dardanelles, two narrow passages linking the Mediterranean and the Black seas. The only direct route from Europe into Asia Minor is at Constantinople, so it has been an extremely strategic possession for land and naval warfare and trade.
Constantinople became the seat of the Eastern Roman, or Byzantine, Empire. It not only was the political capital of much of the Mediterranean and Middle East, but also the seat of the Greek Orthodox Church, rival to the power of the pope in Rome for the souls of Christians everywhere. In the end it was that religious rivalry that spelled Constantinople’s doom.
In the seventh century Muhammad the Prophet founded Islam. By coincidence (or divine intervention) he appeared in Arabia just as the two major Middle Eastern powers, Persia and the Byzantine Empire, had fought each other to an exhausted standstill. He therefore conquered a massive amount of land hand in hand with the spread of his faith. Both Persia and the Byzantines suffered major territorial losses as well as major losses of converts to Islam, who found it less oppressive than the ultraconservative Orthodox Church.
For seven hundred years the forces of Islam and Orthodoxy struggled, with both sides trading ascendancy. By the fifteenth century, however, the Byzantine Empire had shrunk to almost nothing: Constantinople and a handful of Aegean islands. An earlier Islamic threat to the city resulted in the Crusades in the twelfth century, but that too ended in further alienating the Catholic and Orthodox churches. When in 1452 Sultan Mohammed II, son of Murad II, decided to attack Constantinople, European responses to pleas for help were almost nonexistent. England and France were just winding down the very costly Hundred Years War; Germanic and Spanish princes and kings offered aid but sent none. Genoa and Venice, however, did not want to see Constantinople fall into the hands of Arab merchants, and Rome promised aid if the Orthodox Church would submit to papal will. The emperor did all that he could to prepare for the siege. Envoys were sent to Venice, Genoa, the Pope, the Western emperor, the kings of Hungary and Aragon , with the message that, unless immediate military help was provided, the days of Constantinople were numbered. The response was unimpressive. Some Italians, embarrassed at their government’s impotence, came as volunteers. Reluctantly Emperor Constantine XI Paleologus agreed to Rome’s demand, but it netted him a mere 200 archers for his meager defenses as well as the hostility of his people; many claimed they preferred Turkish domination to Roman.
In the spring of 1452 Mohammed II sent 1,000 masons to the Bosphorus to build a fort to protect his army while crossing the straits. Constantine could do little more than lodge a protest. Among his populace were a mere 5,000 native and 2,000 foreign soldiers. The Venetian colony in Constantinople and many citizens in Pera, opposite Constantinople, also stayed, as did Orhan, the Ottoman pretender with his Turks. Some 30,000 to 40,000 civilians who rendered valuable service by repairing the 18-mile-long walls of the city before and during the siege. He had tradition on his side, however, for the triple walls that blocked the city from the landward side had survived twenty sieges, even though at this point they were not in good repair. As of January 1453, he also had the services of Italian soldier of fortune Giovanni Giustiniani, who brought 700 knights and archers. Giustiniani was well known in Europe for his talents in defending walled cities. Mohammed also had some European assistance in the form of a cannon maker named Urban from Hungary, who provided the Muslim army with seventy cannon, including the “Basilica,” a 27-feet-long canon that fired stone balls weighing upwards of 600 pounds. It could only fire seven times a day, but did significant damage to anything it struck.
As part of the Ottoman military preparations, some 16 large and 60 light galleys, 20 horse-ships and several smaller vessels were constructed in the Ottoman arsenal of Gallipoli. The sultan’s army of 80,000 to 100,000 men was assembled in Edirne, the Ottoman capita l, In the Edirne foundry some 60 new guns of various calibres were cast. Some of them threw shots of 240, 300 and 360 kg (530-793 lb), The largest bombard that the Hungarian master Urban made for the sultan fired, according to the somewhat contradictory testimonies of contemporaries, stone balls of 400 to 600 kg (800-1,322 lb), It was transported to Constantinople by 60 oxen.
A single wall that ran the circumference of the city’s seaward sides defended the rest of Constantinople. Mohammed sent his men across the Bosphorus north of the city, so the southern approach to the Mediterranean was open. A chain boom protected the primary harbor, the Golden Horn, across its mouth supported by twenty-six galleys. Thus, if anyone sent relief, the route was open.
Mohammed II arrived on 6 April 1453. He led 70,000 regular troops and 20,000 irregulars called Bashi-Bazouks, whose sole pay was the loot they might gain if and when the city fell. The premier troops were the Janissaries, slave soldiers taken captive in their youth from Christian families and raised in a military atmosphere to serve the sultans. They were heavily armored and highly skilled, and at this time they were beginning to use personal firearms. Mohammed first seized the town of Pera, across the Golden Horn from Constantinople. At first this action was little more than symbolic, but it had serious ramifications later. He then deployed his forces on the city’s western face and began the siege. A single wall near the imperial palace protected the northern end of the city. It was there, the Blachernae, that Constantine placed most of his men.
For twelve days the Muslim cannon pounded the city walls, and on 18 April Mohammed decided that had softened up the defenses sufficiently. The Byzantines easily defended a narrow breach in the walls, killing 200 attackers and driving off the rest without loss to themselves. On the 20th, four ships approached from the south: three Genoese transports with men and supplies from Rome and a Byzantine ship hauling corn from Sicily. After a hard fight with the Muslim fleet they broke through, cleared the boom, and entered the Golden Horn. Mohammed decided he had to control the harbor. He could not pass the chain boom, so he ordered ships dragged overland, through the town of Pera, to the harbor. It was a monumental engineering feat and on 22 April thirty Turkish ships were in the Golden Horn. An agent of the sultan betrayed the Byzantine counterattack, which managed to destroy only a single Turkish ship. In spite of this Turkish accomplishment, it had little effect on the siege.
Mohammed continued his cannonade against the walls. By 6 May it had opened a breach at the Gate of St. Romanus, where the Lycus River enters the city. Giustaniani built a new wall just behind the breach, rather than trying to repair the wall while under fire. The Turks attacked on 7 May but their 25,000 men were thrown back after three hours of fighting. On the 12th another force assaulted a breach in the wall at Blachernae; only quick reinforcement by Constantine and the Imperial Guard stemmed the tide. Mohammed then tried mining the walls. Constantine’s engineer Johannes Grant managed to locate each of the mining attempts and either undermine the mines or destroy the attackers inside with explosives, flooding, or the incendiary Greek fire. None of the fourteen mines succeeded.
Mohammed then determined to scale the walls. His men built a siege tower and rolled it into place before the Charisius Gate, the northernmost opening in the city walls. Muslim artillery fire had destroyed one of the defending towers, and the siege tower was able to provide covering fire for Turks filling in the moat. Constantine’s call for volunteers to attack the siege tower produced spectacular results. The sally surprised the Turkish guards and the Byzantines broke pots of Greek fire on the wooden siege tower. Meanwhile, their compatriots spent the night rebuilding the city wall and its destroyed tower. The next morning Mohammed saw the charred remains of his assault machine smoldering before the newly rebuilt tower in the city wall.
In both camps officers debated the progress of the siege. The defenders were exhausted and running out of supplies. In Mohammed’s camp, some factions wanted to end the siege before a rumored rescue fleet could arrive. The sultan favored those who counseled continuation and decided to launch one more attempt before withdrawing. As the most serious damage to the walls had been inflicted along the Lycus River entrance to the city, it was there he proposed to launch his final assault. Constantine learned of the plan from a spy, but could his dwindling force survive another battle? The Bashi-Bazouks began hurling themselves against the Byzantine defenses at 0200 on 29 May. For two hours the Byzantines slew them with arrows and firearms, but grew increasingly tired in the process. With the first attack repulsed, Mohammed threw in a second wave before the defenders could recover. Even though these were regular troops with better discipline and equipment, the narrow breach provided the defenders with less area to cover and they threw back that assault as well.
After another two hours of fighting the Byzantine troops could barely stand. Mohammed sent in the third wave, made up of Janissaries. Constantine’s exhausted troops managed to repulse them as well. During this fighting, a small band of Turks discovered a small open gate and rushed a handful of men through before it could be closed. They occupied a tower near the Blachinae and raised the sultan’s banner, and the rumor quickly spread that the northern flank had been broken. At the same moment, Giovanni Giustiniani was severely wounded. Hearing of his evacuation, coupled with the report from the north quarter, the defenders began to fall back. Mohammed quickly exploited his advantage. Another assault by fresh Janissaries cleared the space between the walls and seized the Adrianople Gate. Attackers began to pour through.
Constantine XI led his remaining troops into the Turkish onslaught, dying for his city and his empire. Almost all his co-defenders as well as a huge portion of the civilian population joined him, for the Turks went berserk. Mohammed II limited very little of the pillage, reserving the best buildings for himself and banning their destruction. He claimed and protected the Church of St. Sophia, and within a week the Hagia Sophia was hosting Muslim services. Thirty ships of a Venetian fleet sailing to Constantine’s relief saw the Turkish flags flying over the city, turned around, and sailed home.
The looting finally subsided and the bulk of the population that was not killed, possibly 50,000 people, were enslaved. The bastion of Eastern Christianity fell after more than 1,100 years as Constantine the Great’s city. Mohammed II proceeded to conquer Greece and most of the Balkans during the remaining twenty-eight years of his reign.
Western Europe, which had done so little to assist Constantinople, was shocked that it fell after so many centuries of standing against everyone. In Rome, the Catholic Church was dismayed that they would now have no Eastern Christians to convert, for they were all rapidly becoming Muslim. The Eastern Orthodox Church survived, however, for Mohammed allowed a patriarch to preside over the Church. It remained a viable religion, now far from the reach of the Catholic Church’s influence. As such, its survival encouraged others who resented the Catholic Church. Within sixty years Martin Luther led a major protest against the Church, starting the Reformation.
The trading centers of Genoa and Venice feared having to deal with hard-bargaining Arab merchants who now controlled all products coming from the Far East. The major cities of eastern Europe began to fear the Turkish hordes approaching their gates, and for the next 450 years Austria and the Holy Roman Empire carried on the European/Christian struggle against the Ottoman Empire. The Ottoman Turks established themselves as the premier Middle Eastern Muslim power, controlling at their height almost as much as had the Byzantine Empire: the Balkans, the Middle East, much of North Africa, and the eastern Mediterranean.
The flood of refugees from southeastern Europe, especially Greece, brought thousands of scholars to Italy, further enhancing the peninsula’s Renaissance. Italian merchants, shocked at the prices the Muslims charged for spices and silks from the East, began to search for other ways to get those goods. Certainly the age of European exploration came much sooner because of Constantinople’s fall.
Michael Antonucci, “Siege Without Reprieve,” Military History 9, no. 1, April 1992; J. F. C. Fuller, Military History of the Western World, vol. 1 (New York: Funk and Wagnalls, 1954); John J. Norwich, Byzantium: The Decline and Fall (London: Viking, 1995); Sir Steven Runciman, The Fall of Constantinople—1453 (Cambridge: University of Cambridge Press, 1968 ).