Today, July 15, 1099 (June 25, 1099), the First Eastern Crusade attacked Jerusalem. On July 15, 1099, the First Eastern Crusade attacked Jerusalem after a long siege. After the Crusades attacked Jerusalem, massacred and plundered in the Holy City, and then in accordance with the European model, the Crusades established the Crusades in the Mediterranean coast, the Kingdom of Jerusalem and three small affiliated nations: the Kingdom of Edesa, the Republic of Tripoli, and the Principality of Ancona. Because the Crusades brought back a large number of advanced civilizations in the East, and resulted in a large number of peasants disconnected, became free, accelerated the development of Western European hand industry, commerce, as well as an important formation of the modern Renaissance art and middle class commercial civilization, by