Mercians, sent ambassadors to those Irish who were fighting on the side of the invaders, calling upon them to forsake the pagans and remember the old kindness shown in England to Irish soldiers and clergy. The troubles between Norsemen and Danes were probably responsible for the arrival in Ireland in 853 of Amhlaeibh, son of the king of Norway, to receive the submission of the foreigners. This Amhlaeibh is Olaf the White of Norse tradition. Olaf is represented as ruling together with his brother Imhar (O.N. Ívarr). The annals are not very good authority for the relationship of the Norse leaders to one another, and it is quite possible that Ívarr is really Ívarr the Boneless, son to Ragnarr Loðbrók. Under the strong rule of Olaf and Ívarr Dublin became the chief centre of Scandinavian rule in Ireland, and the Danes and Norsemen were to some extent reconciled to one another. The Irish suffered great losses but some brave leaders were found to face the Norsemen. Cennedigh, king of Leix (Queen's County), came upon a party of them laden with booty; they abandoned the spoil and rushed upon Cennedigh with angry barbarous shouts, blowing their trumpets and many of them crying _nui, nui_ (i.e. probably, in the old Norse speech, _knúi, knúi_, 'hasten on, hasten on'). Many darts and spears were thrown and at last they took to their heavy powerful swords. All was however of no avail and Cennedigh won a great victory. Less fortunate was Maelciarain, 'champion of the east of Ireland and a hero-plunderer of the foreigners.' He was expelled from his kingdom by the Leinstermen, who envied him in consequence of his many victories over the Norsemen! The activities of Olaf and Ívarr were not confined to Ireland. In 866 Olaf paid a visit to Scotland, while in 870 both Olaf and Ívarr were present at the siege of Dumbarton. If Ívarr is Ívarr the Boneless, he must then have gone to England and taken part in the martyrdom of St Edmund. In the next year both leaders returned to Dublin with a large number of prisoners--English, Britons and Picts. In 873 Ívarr, 'king of the Norsemen of all Ireland and Britain' died, and about the same time Olaf returned to Norway, possibly to take part in the great fight against Harold Fairhair at Hafrsfjord. The Danes seem to have taken advantage of the removal of Olaf to attempt to throw off the Norse yoke. Fresh fighting took place and the Danes under Albdann, i.e. Halfdanr, king of Northumbria, were defeated on Strangford Lough in 877 with the loss of their leader.