806. I Columbkill again plundered by the Norsemen, and sixty-eight men of the monastery slain.
807. First invasion of the mainland of Ireland by the Norsemen.
815. Turgesius (Thorkel?), chief of the invading Northmen, establishes himself as king of the foreigners in Ireland, making Armagh the capital of the kingdom.
824. Bangor, in the north of Ireland, the seat of the monastery of St. Comhgall, burned, and the bishop and clergy slain by the Northmen.
843. Union of the Picts and Scots under Kenneth M’Alpin, founder of the Scottish dynasty.
853. Arrival of Olaf the White in Ireland. He seizes Dublin, establishes himself there as king, makes an expedition to Scotland, and besieges and takes Dumbarton.
872. Harald Harfagri becomes sole King of Norway; makes an expedition against the western Vikings, who have established their viking station in Orkney, drives them from their haunts, and subdues Shetland, Orkney, the Hebrides, and Man. He gives Orkney and Shetland, as an earldom of Norway, to Rögnvald, Earl of Mœri, father of Hrólf (Rollo), the conqueror of Normandy.
875. Earl Sigurd Eysteinson, who had received the earldom of Orkney from his brother Rögnvald, Earl of Mœri, forms an alliance with Thorstein the Red, son of Olaf the White, King of Dublin. They invade the northern mainland of Scotland, and subdue Caithness and Sutherland as far as Ekkialsbakki. Thorstein the Red is shortly afterwards killed in Caithness; and Earl Sigurd dies, and is buried under a cairn at Ekkialsbakki.
893. Einar (Torf Einar) slays Halfdan Hálegg, one of the sons of Harald Harfagri, and buries him under a cairn in North Ronaldsay.
933. Death of Harald Harfagri. Eirik Bloodyaxe, his son, becomes King of Norway. About this time the name “Scotia” and “Scotland,” previously applied to Ireland, is first given to North Britain, which had formerly been called Caledonia, Pictavia, or Alban.