[Footnote 166: The famous collection which bears the name of Isidorus Mercator contains about sixty spurious Decretals in the first part, covering the first three centuries, and about thirty in the third part; the second part contains the canons of councils. The author makes an adroit use of older documents, and his work is largely a mosaic of genuine fragments (of Papal letters, chronicles, etc.) so pieced together and ante-dated as to father later developments of Papal authority on the earlier Popes. The best edition is that of P. Hinschius (1863), and the best survey of recent study is the article "Pseudoisidor" in Herzog's _Real-Encyclopädie für Protestantische Theologie_. There is a useful chapter in _The Age of Charlemagne_ (1898), by C.L. Wells. The ablest Catholic study of the relation of Nicholas to the collection is Jules Roy's _Saint Nicholas_ (1901). See also _Les Fausses Décrétales_ (1879), of Father Ch. de Smedt. On the general question of the Pope's use of spurious documents see the able Old Catholic work of J. Richterich, _Papst Nikolaus I._ (1903).] [Footnote 167: See _Ep._, cxxx., of Servatus Lupus.] [Footnote 168: _Ep._, xxv.] [Footnote 169: It is not easy to regard Rothrad as the author of the forgery, as he was not deposed until 862. A more probable source of origin is the group of clerics ordained by Ebbo and suspended by Hincmar in 853. Even this seems too late, however, as such a compilation was not the work of a day. But it is very probable that Rothrad took the book to Rome, if it were not already there.] [Footnote 170: _Ep._, xxxiii.] [Footnote 171: The modern writers who have contended that these _tot et talia decretalia statuta_ are not the Isidorean Decretals seem not to have read the whole letter.] [Footnote 172: _Saint Nicholas_, Appendix II. (followed by Dr. Mann, vol. iii.). See also F. Rocquain's _La Papauté au Moyen Âge_ (1881). Hefele (bd. iv., p. 292) admits that Nicholas relied on the forgery.] [Footnote 173: _Papst Nikolaus I._ (1903).] [Footnote 174: P. 116.] [Footnote 175: _Epp._, lxxxii. and cxxxv.] [Footnote 176: P. 131.] [Footnote 177: _Ep._, lxv.] CHAPTER VII JOHN X. AND THE IRON CENTURY