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.

[citation needed] In the summer of 1452, when Rumeli Hisarı was completed and the threat of the Ottomans had become imminent, Constantine wrote to the Pope, promising to implement the union, which was declared valid by a half-hearted imperial court on 12 December 1452.

Furthermore, these Western rulers did not have the wherewithal to contribute to the effort, especially in light of the weakened state of France and England from the Hundred Years' War, Spain's involvement in the Reconquista, the internecine fighting in the Holy Roman Empire, and Hungary and Poland's defeat at the Battle of Varna of 1444.

[40] 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.

[41][page needed][42] 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.

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.

The account of the cannon's collapse is disputed,[6][page needed] given that it was only reported in the letter of Archbishop Leonardo di Chio[60] and in the later, and often unreliable, Russian chronicle of Nestor Iskander.

Girolamo Minotto [el; es; fr; it] and his Venetians were stationed in the Blachernae Palace, together with Teodoro Caristo, the Langasco brothers, and Archbishop Leonardo of Chios.

[75] 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.

Constantine XI only agreed to pay higher tributes to the sultan and recognized the status of all the conquered castles and lands in the hands of the Turks as Ottoman possessions.

Here he encountered some resistance; one of his Viziers, the veteran Halil Pasha, who had always disapproved of Mehmed's plans to conquer the city, now admonished him to abandon the siege in the face of recent adversity.

Believing that the Byzantine defence was already weakened sufficiently, Mehmed planned to overpower the walls by sheer force and started preparations for a final all-out offensive.

[39][95] 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.

[6][page needed][59][60][note 9] 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.

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.

[note 10] 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.

[97] 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.

[citation needed] 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".

On 2 June, the Sultan found the city largely deserted and half in ruins; churches had been desecrated and stripped, houses were no longer habitable, and stores and shops were emptied.

"There were lamentations and weeping in every house, screaming in the crossroads, and sorrow in all churches; the groaning of grown men and the shrieking of women accompanied looting, enslavement, separation, and rape.

"[113][page needed][114] Byzantine historian Doukas claims that, while drunk during his victory banquet, the Sultan ordered the Grand Duke Loukas Notaras to give his youngest son, to him for his pleasure.

"[117] One of the concubines (sex slaves) in the Ottoman Imperial harem of Sultan Mehmet II was Çiçek Hatun, who was herself referred to as a slave-girl captured during the fall of Constantinople.

He issued a proclamation: the citizens of all ages who had managed to escape detection were to leave their hiding places throughout the city and come out into the open, as they were to remain free and no question would be asked.

You will protest that the Turks moved from Asia to Greece a long time ago, that the Mongols established themselves in Europe and the Arabs occupied parts of Spain, having approached through the straits of Gibraltar.

We have never lost a city or a place comparable to Constantinople.The Morean (Peloponnesian) fortress of Mystras, where Constantine's brothers Thomas and Demetrius ruled, constantly in conflict with each other and knowing that Mehmed would eventually invade them as well, held out until 1460.

[138] After the conquest many Greeks, such as John Argyropoulos and Constantine Lascaris, fled the city and found refuge in the Latin West, bringing with them knowledge and documents from the Greco-Roman tradition to Italy and other regions that further propelled the Renaissance.

The fact that Constantinople, which was long "known for being indomitable in the eyes of all," as the Sharif of Mecca said, had fallen and that the Prophet Muhammad's prophecy came true shocked the Islamic world and filled it with a great jubilation and rapture.

Guillaume Dufay composed several songs lamenting the fall of the Eastern church, and the duke of Burgundy, Philip the Good, avowed to take up arms against the Turks.

These émigrés were grammarians, humanists, poets, writers, printers, lecturers, musicians, astronomers, architects, academics, artists, scribes, philosophers, scientists, politicians and theologians.

According to the Encyclopædia Britannica: "Many modern scholars also agree that the exodus of Greeks to Italy as a result of this event marked the end of the Middle Ages and the beginning of the Renaissance".