There can be no doubt that the author had a copy of the _Vulgate_ before him; at least one Biblical passage is correctly given, and it is quoted in its Latin form.[4] It has also been discovered that he had access to an Old Norse paraphrase of a part of the Old Testament, the books of Samuel and of the Kings.[5] It is likely that he was also acquainted with some of the works of Saint Augustine, and perhaps with the writings of certain other medieval authorities. Among these it seems safe to include the _Disciplina Clericalis_, a collection of tales and ethical observations by Petrus Alfonsus, a converted Jew who wrote in the first half of the twelfth century. The _Disciplina_ is a somewhat fantastic production wholly unlike the sober pages of the _Speculum Regale_; nevertheless, the two works appear to show certain points of resemblance which can hardly have been accidental. The _Disciplina_ is a dialog and the part of the son is much the same as in the _King’s Mirror_. In both works the young man expresses a desire to become acquainted with the customs of the royal court, inasmuch as he may some day decide to apply for admission to the king’s household service.[6] The description of courtly manners and customs in the earlier dialog, though much briefer than the corresponding discussion in the Norwegian treatise, has some resemblance to the latter which suggests a possible relationship between the two works. Footnote 4: See below, p. 237. Footnote 5: Storm, “Om Tidsforholdet mellem Kongespeilet og Stjórn samt Barlaams Saga”: _Arkiv for nordisk Filologi_, III, 83-88. Footnote 6: See _Disciplina Clericalis_, fabula xxiv: Migne, _Patrologia Latina_, CLVII, 698-700. The Norwegian author may also have used some of the many commentaries on the books of Holy Writ, in the production of which the medieval cloisters were so prolific. Of the influence of Petrus Comestor’s _Historia Scholastica_ the writer has found no distinct trace in the _King’s Mirror_; but one can be quite sure that he knew and had used the _Elucidarium_ of Honorius of Autun. The _Elucidarium_ is a manual of medieval theology which was widely read in the later middle ages and was translated into Old Norse, probably before the _King’s Mirror_ was written.[7] But our Norwegian author was not a slavish follower of earlier authorities: in his use and treatment of materials drawn from the Scriptures he shows remarkable independence. Remarkable at least is his ability to make Biblical narratives serve to illustrate his own theories of Norwegian kingship. He was acquainted with some of the legends that circulated through the church and made effective use of them. He must also have known a work on the marvels of Ireland[8] and the letter of Prester John to the Byzantine emperor,[9] in which that mythical priest-king recounts the wonders of India. But the chief source of his work is a long life full of action, conflict, thought, and experience. Footnote 7: