Fourth Crusade, 1202-1204
Infamous crusade which became side-tracked into a disastrous involvement with Byzantine politics. The crusade was planned to travel on Venetian ships to Egypt, in return for 85,000 marks and half of their conquests. However, the plan was changed to intervene in Constantinople. The Emperor Isaac II Angelus of Byzantium had been deposed in 1195 after ten years of rule by his brother Alexius III, under whose rule the Empire began to collapse. Alexius, son of Isaac II was probably involved in the decision to travel to Constantinople. In 1202, the crusaders arrived at Venice, but without the money to pay for passage. After some negotiations, the crusaders agreed to capture Zara, once Venetian, now Hungarian, in return for passage. This infuriated the Pope, who excommunicated the entire crusade. Over the winter of 1202-3, Alexius managed to persuade the crusaders to move against Constantinople, in return for 200,000 marks, and the reunification of the Greek church with the church of Rome. On 23 June the crusaders reached Constantinople, where they soon established a base, from where they launched a determined attack on 17 July, which inspired in part by the example of the 95 year old Doge Enrico Dandolo of Venice, managed to capture part of the city. Overnight Alexius III fled, and Isaac II was freed from prison and restored, to rule jointly with his son, now Alexius IV. If the money had been paid, this would not have been a significant disaster, but the money was not available, and in January 1204 the Byzantine nobility overthrew Isaac, who was returned to prison, and Alexius IV, who was executed, and replaced him with the brother in law of Alexius III, who ruled as Alexius V. The crusaders decided to attack the city, and between 11-13 April 1204 launched the first successful attack on Constantinople. After the fall of the city, it was looted for three days, before a short lived Latin Byzantine empire was created. Even after Greek control of Byzantium was re-established, the empire never recovered the strength it had had even in 1200, and the sole effect of the fourth crusade was to weaken Europe's chief protection against the Turks.
How to cite this article: Rickard, J. (25 March 2001), Fourth Crusade, 1202-1204, http://www.historyofwar.org/articles/wars_crusade4th.html