History.com: Pope Urban II orders first Crusade
On November 27, 1095, Pope Urban II makes perhaps the most influential speech of the Middle Ages, giving rise to the Crusades by calling all Christians in Europe to war against Muslims in order to reclaim the Holy Land, with a cry of “Deus vult!” or “God wills it!”
Born Odo of Lagery in 1042, Urban was a protege of the great reformer Pope Gregory VII. Like Gregory, he made internal reform his main focus, railing against simony (the selling of church offices) and other clerical abuses prevalent during the Middle Ages. Urban showed himself to be an adept and powerful cleric, and when he was elected pope in 1088, he applied his statecraft to weakening support for his rivals, notably Clement III.
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