The Venetian ships in the harbour determined to attack the Turks before they could complete the great pontoon which they were preparing to bring up. For some days, however, nothing was done. The attacks on the land walls continued and were beaten back, often with heavy loss. But each day provisions were growing less and the defenders were growing weaker. On the morning of April 28th two Venetian galleys, three smaller ships, and two stored with fire, advanced upon the Turks. They were received with the fire of four cannon. The great galley of Gabrielo Trevisani sank, and one of the smaller ships. Only one of the Turkish ships caught fire. The Venetians who swam to shore when their ships sank were beheaded next day in sight of the defenders of the walls. A bitter revenge was taken. Over two hundred and fifty Turks had at some time or other been captured and lay in the prisons of Constantinople. They were now all beheaded on the walls in sight of their kindred. The horrible act made certain what would be the fate of the city if it fell.
And internal dissensions made the fall seem imminent. The Venetians accused the Genoese and the Genoese the Venetians for the failure of their attack on the Turkish fleet, till Constantine himself called their leaders before him and besought them to be at peace. "The war without," he said, "is enough; by the mercy of God seek not war among ourselves." "So," says Phrantzes, "with much speech at length he pacified them."
Next day and on the first of May the Turkish cannon did some damage; but in some parts the fire was utterly unable to penetrate or dislodge the splendid masonry, and one tower near the Lycus, it is said, was struck by over seventy balls without suffering in the slightest; and the great gun built by the Hungarian mercenary Ourban was dismounted by the fire of the cannon directed by the gallant Genoese engineer Giustiniani, who, with four hundred of his countrymen, manned the walls near the gate of S. Romanus. Mohammed himself was standing by the gun at the moment, and in rage called his troops at once to the assault. They crossed the counter-scarp and began to pull down the scarp where it had been repaired; but again the defenders drove them back.
It was said when the attack began the walls were but half manned, as some of the soldiers had actually left their posts to go home to dine. This laxity, as soon as it was discovered, was of course stopped; but it shows how utterly the people, safe for centuries behind their defences, had forgotten the meaning of war.
The Emperor on the 3rd of May sent out a ship which penetrated through the Turkish fleet, being disguised with Turkish colours, to beg aid. It was plain that if it were much delayed it would be too late. A council of war, indeed, advised the Emperor to escape while it was still possible. The Patriarch and the Senators urged him to go, assuring him that he could then easily gather an army to relieve the city. "The emperor," we are told, "listened to all this quietly and patiently. At last, after having been for some time in deep thought, he began to speak: 'I thank you all for the advice which you have given me. I know that my going out of the city might be of some benefit to me, inasmuch as all that you foresee might really happen. But it is impossible for me to go away: how could I leave the churches of our Lord, and His servants the clergy, and the throne, and my people in such a plight? What would the world say of me? I pray you, my friends, in future do not say to me anything else but, 'Nay, sire, do not leave us.' Never, never, will I leave you. I am resolved to die here with you.' And saying this, the Emperor turned his head aside, because tears filled his eyes; and with him wept the Patriarch and all who were there."[30]
In the next two days a ship was sunk, and the other Christian vessels were compelled to withdraw outside the chain. A Genoese merchant ship was also sunk, and when the merchants of Galata protested, declaring that they were entirely neutral, the Grand Vizier promised to compensate them, when the city was taken.
During the next week the breach by the gate of S. Romanus was daily widened, and on the 7th of May a desperate attack was made upon the walls. But again with splendid courage the Turks were beaten back, though some of the bravest of the defenders fell.
On the 12th of May a breach was made in the walls north of the palace of the Porphyrogenitus, and thousands of Turks poured in. It was only the arrival of Constantine himself, summoned hastily from a council of war, that drove forth the hosts after hot fighting. The Emperor would have pushed through and fought hand to hand in the ditch, we are told, if he had not been held back by his nobles.
From this date every effort was concentrated upon the gate of S. Romanus. There more cannon were directed; and in return men were brought from the fleet, now felt to be useless, to man the walls. One of the towers fell; and new engines were constantly being brought, with clever shelters for the archers. A great erection covered with bulls' hide was destroyed by a gallant attack from the walls, to the surprise of the Turks, who thought the feat impossible. Mines and countermines every day were discovered; every day the defenders were becoming weaker.
On the 23rd an envoy from the Sultan was admitted to the city. Again, and for the last time, Constantine was offered a sovereignty in the Peloponnese, freedom for all who chose to depart, and security for the persons and possessions of all who should choose to remain after the surrender. Again he rejected the offer. No doubt he thought that it was impossible to trust it; nor could the Roman Emperor endure to yield the city that had been but once captured in its age-long history. "We are prepared to die." The last hope failed just after the last bold defiance was returned: the ship sent out returned, to say that nowhere had it found the vessels of the relieving force.