It is capable of demonstration that Christianity was introduced into the Orkney Islands, or at least that missionaries were sent there, long previous to the invasion of Harold Harfagre. Your correspondent W. H. F. mentions that Depping, in the _Histoire des Expéditions Maritimes des Normands_, states that Sigurd, the second nominally, though really the first earl, expelled the Christians from Orkney, and he requests to know Depping's authority; as the circumstance is not alluded to by Torfæus, the Orkneyinga-Saga or Snorro Sturleson, and has been "either overlooked by Barry, or unknown to him." The well-known "Diploma or Genealogical Deduction of the Earls of Orkney," written by the bishop of that diocese in the year 1406, and printed in Wallace's _Account of Orkney_, and in the appendices to Barry's _History_, and the Orkneyinga-Saga, is generally looked upon, from the circumstances under which it was drawn up, as an authentic document of considerable historical value. It is there mentioned, that the Norsemen found the islands inhabited by the Peti and the Papé, whom they exterminated. But I transcribe the words of the Diploma: "Hæc terra sive insularum patria Orcadie fuit inhabitata et culta, duabus nacionibus scilicet Peti et Pape, que due genera naciones fuerant destructe radicitus, ac penitus per Norwegenses de stirpe sive de tribu strenuissimi principis Rognaldi, qui sic sunt ipsias naciones aggressi, quod posteritas ipsarum nacionum Peti et Pape non remansit." Though Chalmers (_Caledonia_, vol. i. p. 261.) is rather inclined to discredit the above account, it seems probable that those Papé were missionaries or priests, who were also found, under precisely the same name, in Iceland when that island was colonised by the Norsemen (Pinkerton's _Enquiry_, vol. ii. p. 297.). I have not my copy of Depping at present by me, and therefore am unable to say whether he explains his use of the word _Christians_ in his mention of their expulsion. It may be that, without going into detail, he accepted, as proved, the identity of the Papé and the priests, and believed himself warranted in making the assertion. But perhaps he might have had some other authority of which I am ignorant, as he attributes the expulsion (according to W. H. F.) to Sigurd, whereas the words of the Diploma are, "per Norwegenses de stirpe sive de tribu strenuissimi principis Rognaldi," by no means limiting the deed to his (Rognald's) immediate successor, though inferentially accusing Sigurd of participation. A careful consideration of the entire passage in Depping, and of his general style, may tend to show whether he relied merely on the Diploma, or whether he had some more definite authority.