Conquest of Constantinople

Between 1346 and 1349 the Black Death killed almost half of the inhabitants of Constantinople. The city was further depopulated by the general economic and territorial decline of the empire. By 1450, the empire was exhausted and had shrunk to a few square kilometers outside the city of Constantinople itself, the Princes' Islands in the Sea of Marmara and the Peloponnese with its cultural center at Mystras. The Empire of Trebizond, an independent successor state that formed in the aftermath of the Fourth Crusade, was also present at the time on the coast of the Black Sea. By 1453, it consisted of a series of walled villages separated by vast fields encircled by the fifth-century Theodosian Walls.

When Mehmed II succeeded his father in 1451, he was just nineteen years old. Many European courts assumed that the young Ottoman ruler would not seriously challenge Christian hegemony in the Balkans and the Aegean. In fact, Europe celebrated Mehmed coming to the throne and hoped his inexperience would lead the Ottomans astray. This calculation was boosted by Mehmed's friendly overtures to the European envoys at his new court.^[6]

By early 1452, work began on the construction of a second fortress (Rumeli hisarı) on the European side of the Bosphorus, several miles north of Constantinople. The new fortress sat directly across the strait from the Anadolu Hisarı fortress, built by Mehmed's great-grandfather Bayezid I. This pair of fortresses ensured complete control of sea traffic on the Bosphorus and defended against attack by the Genoese colonies on the Black Sea coast to the north. In fact, the new fortress was called Boğazkesen, which means "strait-blocker" or "throat-cutter". The wordplay emphasizes its strategic position: in Turkish boğaz means both "strait" and "throat".

In October 1452, Mehmed ordered Turakhan Beg to station a large garrison force in the Peloponnese to block Thomas and Demetrios (despotes in Southern Greece) from providing aid to their brother Constantine XI Palaiologos during the impending siege of Constantinople. Karaca Pasha, the beylerbeyi of Rumelia, sent men to prepare the roads from Adrianople to Constantinople so that bridges could cope with the massive cannons. Fifty carpenters and 200 artisans also strengthened the roads where necessary.^[7] The Greek historian Michael Critobulus quotes Mehmed II's speech to his soldiers before the siege:^[8]

My friends and men of my empire! You all know very well that our forefathers secured this kingdom that we now hold at the cost of many struggles and very great dangers and that, having passed it along in succession from their fathers, from father to son, they handed it down to me. For some of the oldest of you were sharers in many of the exploits carried through by them—those at least of you who are of maturer years—and the younger of you have heard of these deeds from your fathers. They are not such very ancient events nor of such a sort as to be forgotten through the lapse of time. Still, the eyewitness of those who have seen testifies better than does the hearing of deeds that happened but yesterday or the day before.

On 5 April, Sultan Mehmed himself arrived with his last troops, and the defenders took up their positions. As Byzantine numbers were insufficient to occupy the walls in their entirety, it had been decided that only the outer walls would be guarded. Constantine and his Greek troops guarded the Mesoteichion, the middle section of the land walls, where they were crossed by the river Lycus. This section was considered the weakest spot in the walls and an attack was feared here most. Giustiniani was stationed to the north of the emperor, at the Charisian Gate (Myriandrion); later during the siege, he was shifted to the Mesoteichion to join Constantine, leaving the Myriandrion to the charge of the Bocchiardi brothers. Girolamo Minotto and his Venetians were stationed in the Blachernae Palace, together with Teodoro Caristo, the Langasco brothers, and Archbishop Leonardo of Chios.^[9]

The army defending Constantinople was relatively small, totalling about 7,000 men, 2,000 of whom were foreigners. At the onset of the siege, probably fewer than 50,000 people were living within the walls, including the refugees from the surrounding area. Turkish commander Dorgano, who was in Constantinople working for the Emperor, was also guarding one of the quarters of the city on the seaward side with the Turks in his pay. These Turks kept loyal to the Emperor and perished in the ensuing battle. The defending army's Genoese corps were well trained and equipped, while the rest of the army consisted of small numbers of well-trained soldiers, armed civilians, sailors and volunteer forces from foreign communities, and finally monks. The garrison used a few small-calibre artillery pieces, which in the end proved ineffective. The rest of the citizens repaired walls, stood guard on observation posts, collected and distributed food provisions, and collected gold and silver objects from churches to melt down into coins to pay the foreign soldiers.

The Ottomans had a much larger force. Recent studies and Ottoman archival data state that there were some 50,000–80,000 Ottoman soldiers, including between 5,000 and 10,000 Janissaries, 70 cannons, and an elite infantry corps, and thousands of Christian troops, notably 1,500 Serbian cavalry that Đurađ Branković was forced to supply as part of his obligation to the Ottoman sultan—just a few months before, Branković had supplied the money for the reconstruction of the walls of Constantinople.

Mehmed built a fleet (crewed partially by Spanish sailors from Gallipoli) to besiege the city from the sea. Contemporary estimates of the strength of the Ottoman fleet span from 110 ships to 430. A more realistic modern estimate predicts a fleet strength of 110 ships comprising 70 large galleys, 5 ordinary galleys, 10 smaller galleys, 25 large rowing boats, and 75 horse-transports.

At the beginning of the siege, Mehmed sent out some of his best troops to reduce the remaining Byzantine strongholds outside the city of Constantinople. The fortress of Therapia on the Bosphorus and a smaller castle at the village of Studius near the Sea of Marmara were taken within a few days. The Princes' Islands in the Sea of Marmara were taken by Admiral Baltoghlu's fleet.^[10] Mehmed's massive cannons fired on the walls for weeks but due to their imprecision and extremely slow rate of fire, the Byzantines were able to repair most of the damage after each shot, mitigating the effect of the Ottoman artillery.^[11]

Despite some probing attacks, the Ottoman fleet under Baltoghlu could not enter the Golden Horn due to the chain across the entrance. Although one of the fleet's main tasks was to prevent any foreign ships from entering the Golden Horn, on 20 April, a small flotilla of four Christian ships managed to get in after some heavy fighting, an event which strengthened the morale of the defenders and caused embarrassment to the Sultan. Baltoghlu was most likely injured in the eye during the skirmish. Mehmed stripped Baltoghlu of his wealth and property and gave it to the janissaries and ordered him to be whipped 100 times.^[12]

Mehmed ordered the construction of a road of greased logs across Galata on the north side of the Golden Horn and dragged his ships over the hill, directly into the Golden Horn on 22 April, bypassing the chain barrier. This action seriously threatened the flow of supplies from Genoese ships from the nominally neutral colony of Pera and it demoralized the Byzantine defenders.

On the night of 28 April, an attempt was made to destroy the Ottoman ships already in the Golden Horn using fire ships but the Ottomans forced the Christians to retreat with many casualties. Forty Italians escaped their sinking ships and swam to the northern shore. On orders of Mehmed, they were impaled on stakes, in sight of the city's defenders on the sea walls across the Golden Horn. In retaliation, the defenders brought their Ottoman prisoners, 260 in all, to the walls, where they were executed, one by one, before the eyes of the Ottomans. With the failure of their attack on the Ottoman vessels, the defenders were forced to disperse part of their forces to defend the sea walls along the Golden Horn.

The Ottoman army had made several frontal assaults on the land wall of Constantinople, but they were costly failures.^[13] Venetian surgeon Niccolò Barbaro, describing in his diary one such land attack by the Janissaries, wrote:

They found the Turks coming right up under the walls and seeking battle, particularly the Janissaries ... and when one or two of them were killed, at once more Turks came and took away the dead ones ... without caring how near they came to the city walls. Our men shot at them with guns and crossbows, aiming at the Turk who was carrying away his dead countryman, and both of them would fall to the ground dead, and then there came other Turks and took them away, none fearing death, but being willing to let ten of themselves be killed rather than suffer the shame of leaving a single Turkish corpse by the walls.^[14]

After these inconclusive attacks, the Ottomans sought to break through the walls by constructing tunnels to mine them from mid-May to 25 May. Many of the sappers were miners of Serbian origin sent from Novo Brdo under the command of Zagan Pasha.^[15] An engineer named Johannes Grant, a German who came with the Genoese contingent, had counter-mines dug, allowing Byzantine troops to enter the mines and kill the miners. The Byzantines intercepted the first tunnel on the night of 16 May. Subsequent tunnels were interrupted on 21, 23 and 25 May, and destroyed with Greek fire and vigorous combat. On 23 May, the Byzantines captured and tortured two Turkish officers, who revealed the location of all the Turkish tunnels, which were destroyed.^[16]

Preparations for the final assault began in the evening of 26 May and continued to the next day. For 36 hours after the war council decided to attack, the Ottomans extensively mobilized their manpower for the general offensive. Prayer and resting was then granted to the soldiers on 28 May before the final assault would be launched. On the Byzantine side, a small Venetian fleet of 12 ships, after having searched the Aegean, reached the Capital on 27 May and reported to the Emperor that no large Venetian relief fleet was on its way. On 28 May, as the Ottoman army prepared for the final assault, mass religious processions were held in the city. In the evening, a solemn last ceremony of Vespers was held in the Hagia Sophia, in which the Emperor with representatives and nobility of both the Latin and Greek churches partook. Up until this point, the Ottomans had fired 5,000 shots from their cannons using 55,000 pounds of gunpowder. Criers roamed the camp to the sound of the blasting horns, rousing the Ghazis.

Shortly after midnight on Tuesday 29 May, the offensive began. The Christian troops of the Ottoman Empire attacked first, followed by successive waves of the irregular azaps, who were poorly trained and equipped and Anatolian Turkmen beylik forces who focused on a section of the damaged Blachernae walls in the north-west part of the city. This section of the walls had been built earlier, in the 11th century, and was much weaker. The Turkmen mercenaries managed to breach this section of walls and entered the city but they were just as quickly pushed back by the defenders. Finally, the last wave consisting of elite Janissaries, attacked the city walls. The Genoese general in charge of the defenders on land, Giovanni Giustiniani, was grievously wounded during the attack, and his evacuation from the ramparts caused a panic in the ranks of the defenders.^[17]

With Giustiniani's Genoese troops retreating into the city and towards the harbour, Constantine and his men, now left to their own devices, continued to hold their ground against the Janissaries. Constantine's men eventually could not prevent the Ottomans from entering the city and the defenders were overwhelmed at several points along the wall. When Turkish flags were seen flying above the Kerkoporta, a small postern gate that was left open, panic ensued and the defence collapsed. Janissaries, led by Ulubatlı Hasan, pressed forward. Many Greek soldiers ran back home to protect their families, the Venetians retreated to their ships and a few of the Genoese escaped to Galata. The rest surrendered or committed suicide by jumping off the city walls.^[18 ] The Greek houses nearest to the walls were the first to suffer from the Ottomans. It is said that Constantine, throwing aside his purple imperial regalia, led the final charge against the incoming Ottomans, perishing in the ensuing battle in the streets alongside his soldiers. The Venetian Nicolò Barbaro claimed in his diary that Constantine hanged himself at the moment when the Turks broke in at the San Romano gate. Ultimately, his fate remains unknown.

After the initial assault, the Ottoman army fanned out along the main thoroughfare of the city, the Mese, past the great forums and the Church of the Holy Apostles, which Mehmed II wanted to provide as a seat for his newly appointed patriarch to better control his Christian subjects. Mehmed II had sent an advance guard to protect these key buildings.The Catalans that maintained their position on the section of the wall that the emperor had assigned them, had the honor of being the last troops to fall. The sultan had Pere Julià, his sons and the consul Joan de la Via, amongst others, beheaded.

A few civilians managed to escape. When the Venetians retreated over to their ships, the Ottomans had already taken the walls of the Golden Horn. Luckily for the occupants of the city, the Ottomans were not interested in killing potentially valuable slaves but rather in the loot they could get from raiding the city's houses, so they decided to attack the city instead. The Venetian captain ordered his men to break open the gate of the Golden Horn. Having done so, the Venetians left in ships filled with soldiers and refugees. Shortly after the Venetians left, a few Genoese ships and even the Emperor's ships followed them out of the Golden Horn. This fleet narrowly escaped prior to the Ottoman navy assuming control over the Golden Horn, which was accomplished by midday.^[18]

The army converged upon the Augusteum, the vast square that fronted the great church of Hagia Sophia whose bronze gates were barred by a huge throng of civilians inside the building, hoping for divine protection. After the doors were breached, the troops separated the congregation according to what price they might bring in the slave markets. The Venetian Barbaro observed that blood flowed in the city "like rainwater in the gutters after a sudden storm" and that bodies of Turks and Christians floated in the sea "like melons along a canal".^[19]

Mehmed II granted his soldiers three days to plunder the city, as he had promised them and in accordance with the custom of the time.^[20] Soldiers fought over the possession of some of the spoils of war. On the third day of the conquest, Mehmed II ordered all looting to stop and issued a proclamation that all Christians who had avoided capture or who had been ransomed could return to their homes without further molestation, although many had no homes to return to, and many more had been taken captive and not ransomed.

Mehmed himself knocked over and trampled on the altar of the Hagia Sophia. He then ordered a muezzin ascend the pulpit and sound a prayer. The Hagia Sophia was converted into a mosque, but the Greek Orthodox Church was allowed to remain intact and Gennadius Scholarius was appointed Patriarch of Constantinople.

With the capture of Constantinople, Mehmed II had acquired the future capital of his kingdom, albeit one in decline due to years of war. The fall of Constantinople shocked many Europeans, who viewed it as a catastrophic event for their civilization. Many feared other European Christian kingdoms would suffer the same fate as Constantinople. The loss of the city was a crippling blow to Christendom, and it exposed the Christian West to a vigorous and aggressive foe in the East. The Christian reconquest of Constantinople remained a goal in Western Europe for many years after its fall to the Ottoman Empire. Rumours of Constantine XI's survival and subsequent rescue by an angel led many to hope that the city would one day return to Christian hands. Pope Nicholas V called for an immediate counter-attack in the form of a crusade, however no European powers wished to participate, and the Pope resorted to sending a small fleet of 10 ships to defend the city. The short lived Crusade immediately came to an end and as Western Europe entered the 16th century, the age of Crusading began to come to an end.