The declaration of the great founder of Christianity that he "came not to bring peace, but a sword," receives its completest justification in the history of Europe during the sixteenth and seventeenth centuries. Ignorant of the constitution of the human mind, and blind to the absurdity of attempting to enforce opinion, the adherents of the old and of the reformed faith, during these two hundred years, scarcely sheathed their swords. The offenders, it is just to say, were generally, but by no means invariably, the Catholics; and the retaliation of the Protestants was seldom inferior in ferocity to the offence received. The "Thirty Years' War" was the bloodiest, as happily it was the last, scene in this great religious tragedy. The greatest Catholic leader of this period was Wallenstein. After a term of peace, consequent on the Diet of Augsburg in 1555, which secured toleration to Protestantism in Germany, persecution recommenced in 1578, under the weak Emperor Rudolph II. His cousin Ferdinand, Duke of Styria, a pupil of the Jesuits, was the most deadly foe of Protestantism, which had taken deepest root in Bohemia and Transylvania. The incapacity and bigotry of the emperor at last provoked his subjects to bring about his deposition, and, in 1610, he was forced to abdicate in favor of his brother Matthias. He, though himself tolerant, unwisely committed the government to Ferdinand, whose tyranny in ordering the destruction of the Protestant churches in Bohemia, led to the expulsion of his officers and the Jesuits, in May, 1618, and the commencement of the Thirty Years' War. Matthias died in the following year, and Ferdinand was elected emperor.