The beginning of the eleventh century after the proclamation of the Gospel message was a time of crisis and renewal for the Church in the West. Threatened from without by Islam, Christendom was menaced from within by tension between East and West, by the stranglehold of temporal rulers on the property of the Church and the choice of its leaders, by corruption among the minor clergy and by a laity whose faith was mingled with superstition. The author traces the efforts made by successive popes to reform the Church, beginning with Gregory VII. He traces, too, the reasons for the rupture between Roma and Byzantium and the growing resolve to drive back the Muslims which culminated in the crusade preached by Urban II and the establishment of the Christian principalities in the Holy Land. Parallel with these movement came themonastic revival under such leaders as St Bernard the renewed interest in classical learning and science and the great flowering of Romanesque art. Professor Guillemain concludes with an accountof the new dangers - the growth of heresy, renewed struggles between Church and rulers, the collapse of Outremer-and the new respoose to these challenges that reached its apogee under Innocent III.