Mehmet planned to attack the Theodosian Walls, the intricate series of walls and ditches protecting Constantinople from an attack from the west, the only part of the city not surrounded by water. His army encamped outside the city on [[Bright Monday]], [[April 2]], 1453. For weeks Mehmet's massive cannon fired on the walls, but it was unable to sufficiently penetrate them, and due to its extremely slow rate of reloading the Byzantines were able to repair most of the damage after each shot. Meanwhile, Mehmet's fleet could not enter the Golden Horn due to the large chain the Byzantines had laid across the entrance. To circumvent this he built a road of greased logs across Galata on the north side of the Golden Horn, and rolled his ships across. This succeeded in stopping the flow of supplies from Geno]n ships and demoralizing the Byzantine defenders, but did not help in breaching the land walls. Mehmet offered to raise the siege for an astronomical tribute that he knew the city would be unable to pay. When this was declined, Mehmet planned to overpower the walls by sheer force, knowing that the Byzantine defenders would be worn out before he ran out of troops.
On the night of May 22 there was a lunar eclipse, which must have seemed a bad omen to the defenders of the city. On the morning of [[May 29]] the attack began. The first wave of attackers, the bashi-bazouks, were poorly trained and equipped, and were meant only to kill as many Byzantine defenders as possible. The second assault, consisting largely of Anatolians focused on a section of the
[[Blachernae ]] walls in the northwest part of the city, which had been partially damaged by the cannon. This section of the walls had been built much more recently, in the eleventh century, and was much weaker; the crusaders in 1204 had broken through the walls there. The Ottoman attackers also managed to break through, but were just as quickly pushed back out by the Byzantine defenders. The Byzantines also managed to hold off a third attack by the Sultan's elite Janissaries (ironically, most of the Janissaries had been Christian children who were captured by the Ottomans at an early age and trained as warriors), but the Genoan general in charge of the defense, Giovanni Giustiniani, was wounded in the attack, and the Greeks began to panic.
Unfortunately for the Greeks, the Kerkoporta gate in the Blachernae section had been left unlocked, and the Ottomans soon discovered this mistake (there was no question of bribery or deceit by the Ottomans; the gate had simply been overlooked, probably because rubble from a cannon attack had obscured or blocked the door). The Ottomans rushed in. [[Constantine XI]] himself led the last defense of the city, dying in the ensuing battle in the streets.