The Index of Paul is described by the Catholic historian Gretser, but he admits that his information concerning it is derived from the Protestant critic Vergerio. This is the first Index prepared under the direct supervision of the Pope, and the first which bears the official designation of “Index,” the previous lists having been termed catalogues. Editions of Paul’s Index appeared within the year 1559 in Bologna, Venice, Genoa, and Avignon. In 1560, the indefatigable Vergerio reprinted it with a critical, or rather polemical introduction. In the same year, Vergerio published, separately, a treatise (in Latin and Italian) devoted to an attack upon the inquisitors who were responsible for the Index of Paul IV. The title of the Latin edition of Vergerio’s work reads: _Postremus Catalogus Haereticorum Romae Conflatus. 1559. Continens Alios Quatuor Catalogos qui post Decennium in Italia nec non eos omnes qui in Gallia et Flandria post renatum Evangelium fuerunt editi. Cum Annotationibus Vergerii, MDLX Colophon, Corvinus excudebat Pfortzheimii, 1560._ The volume is dedicated to Count Stanislaus. The Italian edition was printed at Ulm and dedicated to the King of Bohemia. The author’s preface is dated from Tübingen. The author states that the Index or Catalogue of 1559 was concocted by the Pope with the concurrence of six inquisitors only. Vergerio goes on to say that when, ten years back, the Pope observed that the Gospel and books favourable to the Gospel were making their way into Italy, he published, in imitation of the divines of the Sorbonne and of Louvain, a small catalogue condemning seventy books. The _Annotations_ of Vergerio, irrespective of the interest of their severe criticisms on the judicial action and the bibliographical blunders of the inquisitors, have proved of service in preserving the most complete enumeration of the Italian Indexes prior to 1559. The sources of information concerning these earlier Indexes are, in fact, so scanty and in the main so untrustworthy that the papal historians themselves have been under the necessity of accepting the record of their Protestant critic. The task of compiling the Index of 1559 had been confided by Paul to Cardinal Caraffa and his associates of the Roman Inquisition. An impression was struck off in 1557, but was cancelled on account of errors that had come to light. The lists as reprinted in 1559 had had the advantage of collation with the Louvain Index of 1558. The papal brief (dated December 21, 1558) follows in the main the text of that of Julius III, of 1550, but there is some new material. One of the earlier sentences is typical of the difficulty of the problems with which the Church found itself confronted: