At this time the impudent charlatan Tetzel was traversing Germany, peddling out his indulgences. The zeal and indignation of Luther were aroused: he preached against the outrage vehemently, and published ninety-five propositions, which contained an irrefutable attack upon the infamous traffic. The propositions were at once declared to be heretical; but no arts of flattery, or terrors of menace, could induce the fearless Luther to recant. Pamphlet after pamphlet proceeded from his pen, assailing the corruptions of the Church; while thousands gathered to listen to his bold denunciations from the pulpit. In 1520 the pope issued a bull of excommunication against Luther and his friends, and his writings were publicly burned at Rome, Cologne, and Louvain. Luther, unintimidated, publicly burned the bull of Papal excommunication at Wittenberg on the 10th of December, 1520. Several of the German princes, and many of the most illustrious nobles, had embraced the doctrines of Luther; so that he was not left without powerful support. Still the world was amazed at the boldness of an obscure monk, who thus ventured to bid defiance to the Catholic clergy, to the fanatic emperor of Germany, and to the pope himself. Luther was summoned by the emperor to appear at the Diet of Worms, and was provided with a safe-conduct from his Majesty. Yet his friends trembled in fear of his assassination. It was upon this occasion, when urged not to expose himself to such danger, that he gave his memorable reply:―― “If there were as many devils in Worms as there are tiles on the roofs of the houses, I would still go there.” As Luther approached Worms, when within three miles of the city, a cavalcade of two thousand citizens came out to honor him with their escort. The Emperor Charles V. presided at the diet. The body was composed of the Archduke Ferdinand, six electors, twenty-four dukes, seven margraves, and many princes, counts, lords, and ambassadors. Luther’s defence was considered by his friends unanswerable; and his foes seemed to think that the only reply to be made was by the dagger of the assassin. To rescue him from this peril, his powerful friends kidnapped him on his return, as we have mentioned, and conveyed him to the Castle of Wartburg, where for ten months he was concealed. These months of retirement he devoted to the translation of the New Testament into German. But his impetuous spirit chafed to escape from the prison-bars which protected him. Through a thousand perils he at length returned to Wittenberg, and there commenced anew his life of tireless zeal in assailing the corruptions of the Church. He drew up a new liturgy for the service of his followers, expurgated of its empty forms; urged the abolition of monasteries, which had mainly become the resort of ignorance and vice; and trampled under his feet the prejudices of papal ecclesiasticism by marrying a nun, Catherine von Bora. Luther was forty-two years of age when he took this important step.