The moment
A crusade preached by Innocent III for Jerusalem ran out of money, took the Christian city of Zara for Venice, then backed a Byzantine claimant. When his promises failed, the crusaders stormed Constantinople on 12–13 April 1204 and plundered it for days, stripping Hagia Sophia and carrying off relics. A Latin emperor ruled until the Byzantines retook the city in 1261. The pope accepted the conquest but condemned the bloodshed when he learned of it.
People: Innocent III, Enrico Dandolo, Baldwin of Flanders