- Cathedrals were grand churches meant to reflect God's glory through their large size, ornate design, and use of innovations like ribbed vaults and flying buttresses which allowed for bigger windows and open spaces. - The Crusades were a series of "Holy Wars" called by the Pope starting in 1096 to retake Jerusalem and the Holy Land from Muslim rule. The First Crusade succeeded in capturing Jerusalem but subsequent Crusades failed to hold territory. - While the Crusades had religious motivations, they also had economic motivations as Crusaders could gain wealth and land if victorious and merchants profited from financing the Crusades.