The document discusses the Crusades that took place between 1096 and 1291 CE. It describes how the Crusades were launched in response to the Muslim conquest of the Holy Land and threats to the Byzantine Empire. The First Crusade succeeded in taking Jerusalem but most later Crusades failed to achieve their goals. The Crusades had major economic, political, and social impacts in Europe and the Middle East, including increasing trade, changing the balance of power among nobles in Europe, and making Christians more intolerant of non-Christians.