The Tower of Mousa, Moseyjar-borg, is twice mentioned by the Saga writers. The earliest notice occurs in the Saga of Egill Skalagrimson, the warrior-poet, and refers to a period about A.D. 900. It is there stated that Björn Brynulfson, fleeing from Norway with Thora Roald’s daughter, because his father would not allow him to celebrate his marriage with her, was shipwrecked on the island of Mousa, landed his cargo, and lived in the Borg through the winter, celebrating his marriage in it, and afterwards sailed for Iceland. The second notice of Mousa,[208] singularly enough, occurs on an occasion somewhat similar to this, when Earl Erlend Ungi fled from Orkney with Margaret, the widow of Maddad, Earl of Athole, and was besieged in the Borg by Earl Harald (Maddadson), who was displeased at the prospect of having Erlend for a step-father. XIII. REMAINS OF THE NORTHMEN. Turning from the pages of the Saga to the scenes of the events which it records, we find, both in the topography and traditions of the localities, and in the customs and characteristics of the people, abundant evidence of the substantial truth of the narrative. The range of territory possessed and occupied by the Norsemen may still be distinguished on the map of Scotland by the prevalence of Norse place-names. In Shetland and Orkney the topography is altogether Norse. In Caithness and Sutherland there is a core of Celtic topography in the central mountain districts, while the Norse names spread out through the valleys, forming a broad fringe along the seaboard, and occupying the whole angle of lowland Caithness. But south of Ekkialsbakki they rapidly thin out, and finally disappear, with a few outlying instances, in Moray. The permanent dominions of the Northmen in the mainland of Scotland were limited to the earldom proper, the southern boundary of which was the Kyle of Sutherland. The Saga says they conquered the country as far south as Ekkialsbakki; and though they sometimes extended their power over parts of Ross and Moray, and even made a raid on one occasion as far south as Fife, they made no permanent lodgment south of the Moray Firth, and their presence in Ross has but slightly affected the topography between the Kyle of Sutherland and the Beauly Firth. In the Hebrides the Norse names, though much disguised by contact with the Celtic, still form a considerable if not a preponderating element in the topography, and their old Norse name, “Sudreyar,” still survives in the title of the Bishop of Sodor and Man. Along the western seaboard of the Scottish mainland, from Cape Wrath to the Mull of Kintyre, the Northmen have left their traces more sparsely, but very distinctly, upon the topography. In Bute, Arran, and the Cumbraes, and on the shores of the Solway Firth, the topography also shows the influence of the Northern element, exerted during the existence of the Norse “Kingdom of Man and the Isles.”