The document discusses reforms to the Catholic Church between 900-1200 CE and the launch of the Crusades. A spiritual revival in the 900s led the Church to restructure and build new places of worship. In 1093, the Byzantine emperor requested Western European assistance in regaining control of the Holy Land, launching the First Crusade. Over the next 300 years, multiple Crusades were initiated to retake lands under Muslim control. The Crusades both reflected and contributed to changes within the Church and its relationship with the Muslim world.