Christian History
Crusades, The
The introduction of feudalism into Palestine resulted in the organization of military orders of knighthood of a semimonastic sort. To the Hospitalers, or Knights of St. John, which had been organized earlier, were added the Templars, who had a house near the site of the Temple in Jerusalem, and the Teutonic Knights, who later distinguished themselves in a crusade against the pagan Prussians of northeastern Europe. Out of such knightly orders sprang chivalry, the flower of feudalism in Europe.
Investiture controversy
Once absolved the emperor hurried home, raised an army and marched on Rome. The pope was aided by the Normans but the contest proved disastrous for Gregory and he died in exile. The quarrel continued until Henry V of Germany compromised with Pope Calixtus II in 1122 and the investiture controversy was settled for a time.
Early missions to Ireland and Britain
The multiplication of churches and schools followed missionary efforts and the English churches were brought into closer contact with the Catholic system on the Continent. Roman Catholic authority later was extended over Ireland and Scotland.
Gregory I and the medieval papacy
Gregory, the first monk to sit on the papal chair, marked the transition from the ancient to the medieval. Appreciative of the old, he preserved orthodoxy while instituting changes that carried the Church forward. He also launched missionary campaigns to unreached barbarians north of the old frontier.