spent his early years in Scotland where he married king Constantine's daughter. It is uncertain whether he fought at Brunanburh, but he came to Northumbria in 941 and captured York. He was expelled from Northumbria in 944 or 945 and retired to Dublin, and the rest of his life was chiefly spent in fighting in Ireland. He was in close alliance with the Norsemen in Man and the Western Islands, and was, for some thirty years, the most powerful Norse ruler in Ireland. Then came the first great blow to Norse rule in Ireland. In 980 Maelsechlainn II, the _ardrí_, won a great victory at Tara over the foreigners of Dublin and the Islands in which Anlaf's son was slain. The power of the kingdom of Dublin was effectually broken. The Norsemen were compelled to liberate all the hostages in their custody, to pay a fine of 2000 oxen and to remit the tribute which they had imposed on all Ireland from the Shannon eastwards to the sea. Anlaf abandoned his authority and retired on a pilgrimage to Iona, where he died in the same year an inmate of its monastery. In the meantime events, fraught with important consequences for Norse rule in that country, were gradually developing in a distant quarter of Ireland. In the province of Munster the Dalcassian line of princes first comes into prominence about the middle of the 10th century, and the two most famous of these princes were the brothers Mathgamhain and Brian, commonly known as Brian Borumha. Together the brothers conquered Munster in spite of the support given to the Irish by the Viking settlers, and when their success aroused Ívarr, the ruler of Limerick, they attacked him and won a great victory at Sulcoit near Tipperary (968). Limerick was captured, Mathgamhain died in 976 and Brian was soon acknowledged king of all Munster. He next became master of Leinster, but his rapid advance brought him into conflict with the _ardrí_ and by a compact made in 998, Maelsechlainn practically surrendered the southern half of Ireland to Brian. The ruler of Dublin at this time was Sigtryggr of the Silken Beard, son of Anlaf and Gormflaith, sister of Maelmordha, king of Leinster. In 1000 Leinster with the support of the Norsemen in Dublin revolted, but Brian defeated them and captured Dublin, giving his daughter in marriage to Sigtryggr and himself marrying Gormflaith. In 1002 Maelsechlainn submitted to Brian and the latter became _ardrí_. There followed twelve years of peace, but Brian's marriage with Gormflaith was his undoing. Quarrelling with her husband, she stirred up Maelmordha of Leinster against him. An alliance was formed between Maelmordha and Sigtryggr, and Gormflaith dispatched embassies to all the Viking settlements in the West, summoning them to the aid of Sigtryggr in a great fight against Brian. Sigtryggr secured the help of Earl Sigurd of the Orkneys and North Scotland by promise of the kingship of Dublin. Ships came from all parts of the Viking world, from Northumbria, from Man