At the commencement of the Reformation, the most strenuous efforts were made by the Inquisitors to check its progress, and various methods were taken to prevent the circulation of the Reformer's works, and especially the Bible, among the people. In 1522 the Pope enjoined the governors of Castile to prevent the works of Luther from being introduced into the kingdom; and orders were given to the Inquisitors to seize and burn all such obnoxious publications! The Emperor Charles V. commissioned the University of Louvain to form a list of dangerous books, a measure which was cordially approved of by the Pope, in a bull which he issued on this subject, in 1539. "The Index was published in 1546," says Llorente, "by the University in all the states of Flanders, six years after a decree had been issued to prohibit the writings of Luther from being read or bought, on pain of death. In 1549, the Inquisitor-general, with the approbation of the Supreme Council, added some new works to the list of those which had been prohibited, and addressed two ordinances to the Inquisitors, enjoining them in the first, not to allow any person to possess them, and in the second, commanding the consultors of the holy office neither to read nor keep them, though the execution of the decrees might throw them into their hands. In 1546, the Emperor commanded the University of Louvain to publish the Index, with additions. This work appeared in 1550, and the prince remitted it to the Inquisitor-general, and it was printed by the order of the Supreme Council, with a supplement composed of books prohibited in Spain, some time after the Council framed another Index, which was certified by the secretary. All the Inquisitions received copies, and a bull from Julius III. which renewed the prohibitions and revoked the permissions contrary to the new bulls: he charged the Inquisitors to seize as many books as they could; to publish prohibiting edicts, accompanied by censures; to prosecute those who did not obey them, as suspected of heresy; and to give an account of the books which they had read and preserved. The Pope added, that he was informed that a great number were in the possession of librarians and private persons, particularly Spanish Bibles mentioned in the catalogue." Nor were the Inquisitors dilatory in obeying the injunctions of his Holiness, and of their superstitious monarch. In 1558, the Inquisitor-general published a very severe edict against all who should retain a single volume of any of the works proscribed. Every Bible was ordered to be strictly examined; nay, the professors in the University were compelled, on pain of excommunication, to give up their Hebrew and Greek Bibles to the commissaries of the Inquisition; and even works on medicine were seized, although they were not mentioned in the Index.