The fourth crusade is also known as the “crusade of the Venetians” due to the leading role played by the Serenissima in this venture which concluded with the taking of Constantinople and the beginning of the Eastern Latin Empire.
The fourth crusade was initially sought by Pope Innocent III, but he forbade it when the Republic of Venice turned the anti-Islam crusade into a private campaign of politico-commercial expansionism. This crusade represents a great success in the history of Venice since the city not only gained possession of the territories of Byzantium but also plundered its treasures, many of which today form part of the artistic heritage of the Church of St. Mark and its Museum.
The crusading ideal reigned between the end of the 11th century and the early 12th century and very likely arose following serious acts of religious intolerance suffered by Christian pilgrims in the Holy Land.
Venice came to the Crusaders’ aid later than other sea powers; more precisely, only after it had realistically evaluated the political and economic effects. The events in the Holy Land troubled Venice also due to rivalry with other seafaring Republics, especially Genoa and Pisa, who supported the Crusaders’ action. Moreover the theatre of operations included a reaction by European States against the increasingly threatening Arab expansion into Christian lands. Over and above the Arabs, there was another Islamic power seeking to conquer the West: the Seljuk Turks who took control of Syria and Palestine at the end of the 11th century. This period determined the Christian States’ position on the offensive of the Crusades and with time was the determining cause of Venice’s long lasting conflict with the Turks.
Venice achieved the peak of its glory with the 4th Crusade, of which the Doge Enrico Dandolo (1192 -1205) was both artificer and protagonist.
At the end of the 12th century diplomatic and political relations between Constantinople and Venice were apparently cordial and Venice continued to benefit from its ancient trade concessions in the East. Nevertheless Venice had not yet erased the memory of a blow inflicted at Constantinople in 1171 by the emperorManuel when ten thousand Venetians had been arrested and massacred. When the occasion presented itself Venice did not renounce revenge, taking advantage of usurpations in the East for succession to the empire on the death of emperor Manuel Comnenus. It appears that even before the Crusade troops gathered in Venice in 1202, to be taken to the East in aid of the Christians against the Sultan of Egypt, there had been secret agreements between the Christian commander barons and the Doge Enrico Dandolo: instead of going to Egypt the expedition would head first to Constantinople and put the young and persecuted Alexis back on the usurped throne. He had promised, should he become emperor once more, to supply considerable means for the Christian venture.
In spite of excommunications by Pope Innocent III, who saw failure of the expedition against the Unbelievers, the new plan was accepted. In April 1203 the Crusaders’ army reached Constantinople, attacked the city and took it. The young emperor they restored to the throne was killed in an uprising. The Crusaders conquered the city for the second time on their own account in 1204 and, proclaiming the fall of the ancient Eastern Empire, they established, on old Dandolo’s proposal, that the whole territory and its vast riches should be divided among the participants. Its place would be taken by the new Latin Empire of Constantinopleof which the Venetians would own one quarter and a half.
A great colonial empire was thus formed with an almost uninterrupted chain of ports and stop-off points from Dalmatia to Constantinople and beyond, into the Black Sea. Venice gained an immense booty of riches – gold, marble and artworks (including the four horses of St. Mark’s) – and its sea power was enormously increased.