"To give you the city is not within our power, nor that of any of its inhabitants, because we have all, by universal decree, resolved to die in the city and to have no mercy on your lives." With these words, the Eastern Roman Emperor Constantine XI Palaiologos (1405-1453) responded to Sultan Mehmet II's (1432-1481) request to hand over the city of Constantinople to the Ottomans in exchange for the safety of its inhabitants. On the evening of May 28, 1453, in the majestic Cathedral of Saint Sophia, in the presence of the Orthodox and Catholic clergy (united for the first time in centuries against the common enemy), Emperor Constantine XI prostrated himself before the Cross and then spoke: "I know that the hour has come and that the enemy of our faith threatens us, and for this reason I entrust to you, to your valor, this splendid and famous city, our homeland and queen of all others[...] There are four great causes worth dying for: faith, homeland, family, and the basileus. Now you must be ready to sacrifice your lives for these things, just as I am ready to sacrifice my own life[...]". Thus decreeing - accompanied by the ringing of bells and enemy bombardments - the beginning of the last heroic resistance of the Roman Empire. Of the last clash between East and West. Having ascended the throne just five years before the siege, in 1448, Constantine inherited a moribund empire far from its former glory. This, however, did not stop him from attempting to revive its doomed fortunes: he promoted the construction of churches and trade with the Ottomans themselves and the Genoese of Galata, striving to secure the empire's brightest future with the limited economic resources at his disposal.

Once a breach had been made in the—until then—impregnable Theodosian walls, Constantine XI stripped himself of his imperial insignia and, joining the last remaining soldiers, launched a heroic and desperate charge against the Turks, uttering the phrase: "The city has fallen, yet I am here." The last Byzantine emperor then vanished from history: no one saw him again, and his body was never found.

The death of Constantine XI marked not only the departure of an emperor, but also the disappearance of an entire world: the Byzantine one. Today, the emperor is considered a national hero in Greece (as well as a saint and martyr of the Orthodox Church), the last bastion of Christian resistance to the Ottomans.