Hrafn the Red, whose denunciation of the raven-banner as the earl’s devil may not altogether be accounted for by the fervour of his Christianity, was chased into the river, where he was in danger of being drowned by the rising tide. In this emergency he made a vow as follows:—“Thy dog, Apostle Peter, hath run twice to Rome, and he would run the third time if thou gavest him leave.” The Irish Chronicle states that the full tide in Dublin Bay on the day of the battle coincided with sunrise, and that the returning tide in the evening aided in the destruction of the defeated foreigners. The date assigned by the Chronicle for the battle is Good Friday, 23d April 1014. It has been found by astronomical calculation that the full tide that morning did coincide with sunrise—a remarkable attestation of the authenticity of the narrative. Footnote 30: See the account of him in the Saga, chap. v. and note. Footnote 31: Rattar Brough, a little to the east of Dunnet Head, seems to be the modern form of Rauda Biorg. Footnote 32: See the Saga account, chap. xxiii. and note. The dates do not bear out the statement that Thorfinn was Earl for seventy years. Footnote 33: Fordun, v. 24. Footnote 34: Saga Magnus Berfoetts, Heimskringla, chap. xxv. Footnote 35: Chron. Manniæ, Munch’s edition, p. 59. Footnote 36: See the account of his death in the Saga, chap. xxxix. His feast days were 16th April and 13th December, the former commemorating his death, and the latter the removal of his relics from Birsay by Bishop William. (Den Norske Kirkes Historie af R. Keyser: Christiania, 1856, p. 162.) Footnote 37: The Earls of Athole seem at this time to have occupied the _rath_ or fortress at Logierait. It is mentioned in one of the Scone charters as the capital of the earldom in the 12th century. (Lib. Eccles. de Scon, p. 35.) Footnote 38: This was the occasion in which he and his men spent the Yule-feast day in the Orkahaug, which seems to be Maeshow. See the Saga, chap. xci. Footnote 39: See the notice from the Saga of Egill Skalagrimson, in the chapter on Mousa. Footnote 40: Some years after his death Earl Rögnvald was canonised, but his name is not commemorated in any of the dedications now remaining in the Islands. Footnote 41: Munch, Chron. Manniæ, p. 84. Footnote 42: Fordun’s Annals, xvi. Footnote 43: