After receiving inadequate payments for preparing the defenses of this city, a Hungarian engineer disastrously defected to its enemies. As part of an erstwhile campaign to restore Isaac II to the throne, this city was sacked in 1204 during the Fourth Crusade. A large portion of this city was burned during the Nika riots. This city finally fell after canon fire opened a breach in its walls near the Gate of Romanos. For 10 
After receiving inadequate payments for preparing the defenses of this city, a Hungarian engineer disastrously defected to its enemies. As part of an erstwhile campaign to restore Isaac II to the throne, this city was sacked in 1204 during the Fourth Crusade. A large portion of this city was burned during the Nika riots. This city finally fell after canon fire opened a breach in its walls near the Gate of Romanos. For 10 points, name this city that fell to Turkish forces under Mehmet the Conqueror on May 29th, 1453.
After receiving inadequate payments for preparing the defenses of this city, a Hungarian engineer disastrously defected to its enemies.
Constantinople