In 1559, the responsibility for the censorship of literature was first assumed directly by the papal authority through the publication of the _Index Auctorum et Librorum Prohibitorum_, of Paul IV, the first of a long series of papal Indexes, aggregating, up to 1899, forty-two in all. It does not appear to have been the intention either of Pope Paul IV or of his successors that the responsibility for the system of censorship should be retained under the exclusive direction of the papal authorities, and I find no record of objections having been raised to the publication of the Indexes prepared by such representatives of the Church as the theological faculties of the Universities of Louvain and of Paris, or by the Inquisition of Spain. There were, however, very material differences between the lists as shaped in Rome of works condemned as heretical and the similar lists issued within the same period in Louvain, Paris, or Valladolid; books of undoubted heresy included in one Index would fail to find place in another, and it is difficult to arrive at any consistently followed principle or policy by which the selections of the different compilers were determined. In the absence of any definite instruction to the contrary, it might at first be assumed from the wording of the prohibitions that any and all of the Indexes, published under the direction of such ecclesiastical authorities as those specified, must have been intended to be equally binding on all the faithful, irrespective of political or ecclesiastical boundaries. We know, however, as a matter of history, that, in the majority of cases, no attempt was made to enforce the prohibitions of the Index outside of the territory of the State in which it had been promulgated. It is difficult to secure any trustworthy information as to the precise range of the effectiveness of these prohibitions, but it seems probable that the Roman Indexes were held to be in force outside of the immediate territory of the Church only after they had been formally accepted and promulgated by the authorities, ecclesiastical and political, of the individual States, such as Spain, France, the Empire, etc. The Index of 1559 was, as stated, the first of the series of papal Indexes; but as early as 1542, the Inquisition of Rome had promulgated a special edict prescribing penalties for the reading of heretical or of doubtful books, and in 1545 was published the first Italian list of prohibited books and authors. In 1571, under Pope Pius V, the task of compiling the papal Indexes was confided to a body organised under the name of the Congregation of the Index, which is still (1906) carrying on its work.