Before the Fall of Constantinople in 1453 he subsidized the repair of fortifications at his own expense and he was wounded in the early hours of the sack. He managed to escape the carnage by dressing up a dead body in his cardinal's robes. While the Turks were cutting off its head and parading it through the streets, the real cardinal was shipped off to Asia Minor with a number of insignificant prisoners, as a slave and later found safety in Crete. He composed a series of letters describing the events of the siege. He warned of the danger of further expansion of the Turks in the multiple letters and even seems to be the earliest eyewitness to have compared Mehmed II with Alexander the Great.