On July 15, 1099, the Crusaders of the First Eastern Expedition captured Jerusalem after a long siege.

After the Crusaders conquered Jerusalem, they massacred and looted in the Holy City, and then established the Crusader State in the area occupied by the Crusaders on the Mediterranean coast according to the European model. The Kingdom of Jerusalem and three subsidiary small states: the Kingdom of Idsaab, the Kingdom of Tripoli, and the Duchy of Antioch. Because the Crusaders brought back a large number of eastern progressive civilizations, and led to a large number of serfs to dissolve their dependence and become free people, accelerating the development of handicrafts and commerce in Western Europe. It was also an important factor in the Renaissance and modern middle-class commercial civilization, shaping the modern and prosperous Europe.

After the Crusaders captured Jerusalem, they looted massively

Comment: War will bring disaster to both sides, but one side will also gain something.