My trade offer URL

The Sack of Constantinople, April 1204, was the diversion of the Fourth Crusade from the Holy Land to attack, capture, and pillage the Byzantine city of Constantinople and is widely regarded as a shocking betrayal of principles out of greed.

The Fourth Crusade was corrupted from its purpose early on. In order to repay Venice for shipping most of the crusaders eastward, they were obliged to seize Zara on the Adriatic from Christian Hungary on Venice’s behalf. Meanwhile exiled Byzantine prince Alexius offered a cash reward if he were put on the Byzantine throne.

The crusaders therefore sailed to Constantinople and in July 1203 set up Alexius as emperor. In February 1204 the new emperor was murdered and replaced by courtier Alexius Ducas, who told the crusaders to leave. The crusaders responded by laying siege to Constantinople. A first assault on the city’s defenses was repelled with heavy losses, but on 12 April the crusaders were successful. For three days the army pillaged at will, and then the nobles imposed order and began a more systematic looting of the greatest city in Christendom. The crusader nobleman Baldwin of Flanders was set up as emperor, but most Byzantines refused to recognize him, and the empire fragmented into four quarreling states.

After the city's sacking, most of the Byzantine Empire's territories were divided up among the Crusaders. Byzantine aristocrats also established a number of small independent splinter states—one of them being the Empire of Nicaea, which would eventually recapture Constantinople in 1261 and proclaim the reinstatement of the Empire.

However, the Byzantine Empire was left much poorer, smaller, and ultimately less able to defend itself against the Seljuk and Ottoman conquests that followed. The restored Empire never managed to reclaim its former territorial or economic strength, and eventually fell to the rising Ottoman Empire in the 1453 Siege of Constantinople, leading to the end of the Byzantine Empire. The actions of the Crusaders thus directly accelerated the collapse of Christendom in the east, and in the long run helped facilitate the later Ottoman conquests of Southeastern Europe.