Siege of Zara, (1202), a major episode of the Fourth Crusade; the first attack on a Christian city by a crusading army, it foreshadowed the same army’s assault on Constantinople, the Byzantine capital, in 1203–04. Zara (modern Zadar, Croatia), a vassal city of the Venetian republic, rebelled against Venice in 1186 and placed itself under the protection of King Béla III of Hungary. Anxious to reassert their claims over Zara, the Venetians diverted the Fourth Crusade from its original objectives, Palestine and Egypt, to attack the city.
Pope Innocent III (1198–1216) had learned of the proposed attack before the fleet set sail and sent letters to Venice forbidding the action. Even the threat of excommunication failed to deter the armies, although their reluctance to accede to the papal directive is doubtless a reflection of the severe financial problems that confronted them. The crusaders, who came from France, had agreed to pay the Venetians to transport them to the Holy Land, but they found themselves without sufficient funds. Faced with the threat of abandonment of the crusade and forfeiture of money already paid, they acquiesced to the Venetian proposal to lay siege to Zara.
The fleet sailed from Venice in early October 1202, arriving at Zara on November 10. The city surrendered after two weeks of siege and assault; the garrison and the inhabitants were spared. The expedition wintered in Zara, during which time the decision was made to attack Constantinople the following spring.