1202-1204 AD
The Fourth Crusade (1202-1204) is the most infamous of all the Crusades. Originally intended to march on Egypt and then Jerusalem, the Crusaders were diverted by Venetian interests and political intrigue to Constantinople, the capital of the Byzantine (Eastern Orthodox) Empire. In April 1204, the Crusaders sacked Constantinopleβa Christian cityβlooting churches, destroying icons, and committing atrocities that shocked even medieval standards.
The sack of Constantinople deepened the schism between the Roman Catholic and Eastern Orthodox Churches that had begun in 1054. The Byzantines never forgave the Latin Christians for what they considered the greatest betrayal in history. The Crusaders established a 'Latin Empire' in Constantinople that lasted until 1261, but the Eastern Empire was fatally weakened and would eventually fall to the Ottoman Turks in 1453.
Pope Innocent III, who had called the Crusade, was horrified by the sack and excommunicated the participants, but the damage was done. Key Sources: The Anonymous Author of the Deeds of the Romans; Niketas Choniates, O City of Byzantium; Pope Innocent III's letters