1202–1261

The Fourth Crusade and the Sack of Constantinople

The crusaders were in debt to the Venetians. They first sacked the Christian city of Zara against Pope Innocent III's prohibition. Then, drawn into a Byzantine dynastic dispute, they took and sacked Constantinople in 1204. They never reached the Holy Land. A Latin Empire was established in Byzantium's place, lasting until 1261, with Baldwin of Flanders as emperor.

East and West were formally reunited for a time under a Catholic patriarch. Innocent III was initially outraged but came to see it as God's will. Most of the Greek people and clergy, however, regarded it as the lowest point in East-West relations.

The hatred of the Latins born of this sack undid every later attempt at reunion. It also hastened the fall of a weakened Byzantium in 1453.