Constantine XI (1449-1453) and the capture of Constantinople
At the beginning of April, 1453, the siege of the great city began. It was not only the incomparably greater military forces of the Turks that contributed to the success of the siege. Muhammed II, called by Barbaro, this perfidious Turk, dog-Turk,was the first sovereign in history who had at his disposal a real park of artillery. The perfected Turkish bronze cannons, of gigantic size for that time, hurled to a great distance enormous stone shots, whose destructive blows the old walls of Constantinople could not resist. The Russian tale of Tsargrad states that the wretched Muhammed conveyed close to the city walls cannons, arquebuses, towers, ladders, siege machinery, and other wall-battering devices. The contemporary Greek historian, Critobulus, had a good understanding of the decisive role of artillery when he wrote that all the saps made by the Turks under the walls and their subterraneous passages proved to be superfluous and involved only useless expense, as cannons decided everything.
In the second half of the nineteenth century, in several places of Stamboul, one might still see on the ground the huge cannon shots which had hurtled over the walls and were lying in nearly the same places in which they had fallen in 1453. On April 20 the only piece of good fortune for the Christians in the whole siege took place: the four Genoese vessels which had come to the aid of Constantinople, defeated the Turkish fleet in spite of its far superior numbers. One may easily imagine, wrote a recent historian of the siege and capture of the Byzantine capital, Schlumberger, the indescribable joy of the Greeks and Italians. For a moment Constantinople considered itself saved. But this success, of course, could have no real importance for the outcome of the siege.