The terrible events of 1527, when Charles V.'s mercenaries sacked Rome, ended the cynical paganism of the Italian Renaissance. The Church began to prepare seriously to meet the Protestants with their own weapons of energy and casuistry. The Inquisition was revived to
destroy heretical books and hear charges of heresy. Ignatius Loyola, a Spanish knight, founded the Society of Jesus, a mobile force of highly trained enthusiasts, for exacting labour-missionary work in Africa or Japan, intrigue against Protestant governments, and for preaching and education in Catholic countries. A great Council of the Church met at Trent, in North Italy, in 1545: it spent eighteen years in reforming the Church's discipline. This Counter Reformation regained much of the lost ground during the century from 1547 to 1648.
The first effort of the Counter Reformation was Charles V.s attempt to restore religious order in Germany. In 1547 he was at last at peace with France and Luther was dead. After winning a delusive victory and suffering humiliating betrayals and defeats, he made the Peace of Augsburg in 1555; each German prince might enforce his own religion-Roman or Lutheran-in his own dominions: Cuius Regio, eius religio (" Whose is the kingdom, his the religion ") was the maxim which summarised the exaltation of monarchy. Charles then abdicated and left the Empire to his brother Ferdinand, already ruler of Bohemia and Hungary. From him the later Habsburg emperors descend. Ail his other dominions he left to his son Philip II. of Spain. The success of the German princes encouraged the French nobility to begin a similar revolt, and Philip's personality was the prime cause of a rebellion in his Netherlands dominions which soon followed. A forty years struggle ensued.
The Reformation, which on the spiritual side was an assertion of individual judgment against that of the Church, tended in Lutheran and Anglican areas to the aggrandisement of regal power and the control of the Church by the State-the principle known as Erastianism. Where Calvinism prevailed, its tendency was towards republican or oligarchic government, which gave the Church a show of independence on condition of its serving class and national ideals.