When
Mehmed II succeeded his father in 1451, he was 19 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. But Mehmed's mild words were not matched by his actions. By early 1452, work began on the construction of a second
fortress (
Rumeli hisarı) on the European side of the
Bosphorus, Around the same time, the captains of the Venetian ships that happened to be present in the
Golden Horn offered their services to the Emperor, barring contrary orders from
Venice, and Pope Nicholas undertook to send three ships laden with provisions, which set sail near the end of March. From the
Kingdoms of Naples and
Sicily arrived in Constantinople the
condottiero Gabriele Orsini del Balzo, duke of
Venosa and count of
Ugento, together with 200 Neapolitan archers, who died fighting for the defense of the capital of the Byzantine Empire. Meanwhile, in Venice, deliberations were taking place concerning the kind of assistance the Republic would lend to Constantinople. The
Senate decided upon sending a fleet in February 1453, but the fleet's departure was delayed until April, when it was already too late for ships to assist in battle. Further undermining Byzantine morale, seven Italian ships with around 700 men, despite having sworn to defend Constantinople, slipped out of the capital the moment Giustiniani arrived. At the same time, Constantine's attempts to appease the Sultan with gifts ended with the execution of the Emperor's ambassadors. that closed off the entrance to the Golden Horn in 1453, now on display in the
İstanbul Archaeology Museums Great Chain of the Golden Horn Fearing a possible naval attack along the shores of the Golden Horn,
Emperor Constantine XI ordered that a
defensive chain be placed at the mouth of the harbour. This chain, which floated on logs, was strong enough to prevent any Turkish ship from entering the harbour. This device was one of two that gave the Byzantines some hope of extending the siege until the possible arrival of foreign help. This strategy was used because in 1204, the armies of the Fourth Crusade successfully circumvented Constantinople's land defences by breaching the
Golden Horn Wall, which faces the Horn. Another strategy employed by the Byzantines was the repair and fortification of the land wall (Theodosian walls). Constantine deemed it necessary to ensure that the
Blachernae district's wall was the most fortified because that section of the wall protruded northwards. The land fortifications consisted of a wide moat fronting inner and outer
crenellated walls studded with towers every 45–55 metres. {{CSS image crop | Image = Byz1453.png | bSize = 768 | cWidth = 324 | cHeight = 219 | oTop = 104 | oLeft = 382 | Location = left
Strength The army defending Constantinople was relatively small, totalling about 7,000 men, 2,000 of whom were foreigners. The population decline also had a huge impact upon Constantinople's defense capabilities. At the end of March 1453, Constantine ordered a census of districts to record how many able-bodied men were in the city and whatever weapons each possessed for defense. George Sphrantzes, the faithful chancellor of the last emperor, recorded that "in spite of the great size of our city, our defenders amounted to 4,773 Greeks, as well as just 200 foreigners". In addition there were volunteers from outside, the "Genoese, Venetians and those who came secretly from Galata to help the defense", who numbered "hardly as many as three thousand", amounting to something under 8,000 men in total to defend a perimeter wall of twelve miles. 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. Contemporaneous Western witnesses of the siege, who tend to exaggerate the military power of the Sultan, provide disparate and higher numbers ranging from 160,000 to 300,000 (
Niccolò Barbaro: 160,000; the Florentine merchant Jacopo Tedaldi and the Great Logothete
George Sphrantzes: 200,000; the Cardinal Isidore of Kiev and the Archbishop of
Mytilene Leonardo di Chio: 300,000).
Ottoman dispositions and strategies , cast by Munir Ali in 1464, is similar to
bombards used by the Ottoman besiegers of Constantinople in 1453 (British
Royal Armouries collection). 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 (Tedaldi: 110; Barbaro: 145; Ubertino Pusculo: 160, Isidore of Kiev and Leonardo di Chio: 200–250; (Sphrantzes): 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. Before the siege of Constantinople, it was known that the Ottomans had the ability to cast medium-sized cannons, but the range of some pieces they were able to field far surpassed the defenders' expectations. The Ottomans deployed a number of cannons, anywhere from 12 to 62 cannons. They were built at
foundries that employed Turkish cannon founders and technicians, most notably Saruca, in addition to at least one foreign cannon founder,
Orban (also called Urban). Most of the cannons at the siege were built by Turkish engineers, including a large bombard by Saruca, while one cannon was built by Orban, who also contributed a large bombard. Orban, a
Hungarian (though some suggest he was
German), was a somewhat mysterious figure. His cannon was named "
Basilica" and was able to hurl a stone ball over a
mile (1.6 km). Orban initially tried to sell his services to the Byzantines, but they were unable to secure the funds needed to hire him. Orban then left Constantinople and approached Mehmed II, claiming that his weapon could blast "the walls of
Babylon itself". Given abundant funds and materials, the Hungarian engineer built the gun within three months at Edirne. However, this was the only cannon that Orban built for the Ottoman forces at Constantinople, and it had several drawbacks: it took three hours to reload; cannonballs were in very short supply; and the cannon is said to have collapsed under its own recoil after six weeks. The account of the cannon's collapse is disputed, given that it was only reported in the letter of Archbishop
Leonardo di Chio and in the later, and often unreliable, Russian chronicle of
Nestor Iskander. Having previously established a large foundry about away, Mehmed now had to undertake the painstaking process of transporting his massive artillery pieces. In preparation for the final assault, Mehmed had an artillery train of 70 large pieces dragged from his headquarters at Edirne, in addition to the bombards cast on the spot. This train included Orban's enormous cannon, which was said to have been dragged from Edirne by a crew of 60 oxen and over 400 men. There was another large bombard, independently built by Turkish engineer Saruca, that was also used in the battle. Mehmed planned to attack the Theodosian walls, the intricate series of walls and ditches protecting Constantinople from an attack from the West and the only part of the city not surrounded by water. His army encamped outside the city on 2 April 1453, the Monday after
Easter. The bulk of the Ottoman army was encamped south of the Golden Horn. The regular European troops, stretched out along the entire length of the walls, were commanded by Karadja Pasha. The regular troops from
Anatolia under
Ishak Pasha were stationed south of the
Lycus down to the Sea of Marmara. Mehmed himself erected his red-and-gold tent near the
Mesoteichion, where the guns and the elite Janissary regiments were positioned. The
Bashi-bazouks were spread out behind the front lines. Other troops under Zagan Pasha were employed north of the Golden Horn. Communication was maintained by a road that had been destroyed over the marshy head of the Horn. The Ottomans were experts in laying siege to cities. They knew that in order to prevent diseases they had to burn corpses, sanitarily dispose of excrement, and carefully scrutinize their sources of water.
Byzantine dispositions and tactics The city had about 20 km of walls (land walls: 5.5 km; sea walls along the Golden Horn: 7 km; sea walls along the Sea of Marmara: 7.5 km), one of the strongest sets of fortified walls in existence. The walls had recently been repaired (under John VIII) and were in fairly good shape, giving the defenders sufficient reason to believe that they could hold out until help from the West arrived. In addition, the defenders were relatively well-equipped with a fleet of 26 ships: five from Genoa, five from
Venice, three from Venetian
Crete, one from
Ancona, one from
Aragon, one from France, and about 10 from the empire itself. On 5 April, the Sultan 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. and his Venetians were stationed in the
Blachernae Palace, together with Teodoro Caristo, the Langasco brothers, and Archbishop Leonardo of Chios. To the left of the emperor, further south, were the commanders Cataneo, who led Genoese troops, and Theophilus Palaeologus, who guarded the
Pegae Gate with Greek soldiers. The section of the land walls from the Pegae Gate to the Golden Gate (itself guarded by a Genoese called Manuel) was defended by the Venetian Filippo Contarini, while Demetrius Cantacuzenus had taken position on the southernmost part of the Theodosian wall. The sea walls were guarded more sparsely, with Jacobo Contarini at
Stoudion, a makeshift defence force of Greek monks to his left hand, and
Prince Orhan at the
Harbour of Eleutherios. Genoese and Catalan troops were stationed at the
Great Palace; Cardinal Isidore of Kiev guarded the tip of the peninsula near the boom. Finally, the sea walls at the southern shore of the Golden Horn were defended by Venetian and Genoese sailors under
Gabriele Trevisano. Two tactical reserves were kept behind in the city: one in the Petra district just behind the land walls and one near the
Church of the Holy Apostles, under the command of
Loukas Notaras and Nicephorus Palaeologus, respectively. The Venetian
Alviso Diedo commanded the ships in the harbour. Although the Byzantines also had cannons, the weapons were much smaller than those of the Ottomans, and the
recoil tended to damage their own walls. According to
David Nicolle, despite many odds, the idea that Constantinople was inevitably doomed is incorrect and the situation was not as one-sided as a simple glance at a map might suggest. It has also been claimed that Constantinople was "the best-defended city in Europe" at that time. ==Siege==