[K. of Ireland 916-19], captured and drowned a murderer in 907 who had violated the sanctuary of Armagh; he also revived the ancient Fair of Taitiu in 916. He campaigned repeatedly against the Danes and Norse in Ireland, but was mortally wounded in battle near Dublin, 15 Sep 919, fighting against Sigtryg (Sitric) II [K. of Dublin, afterward K. of York]. He m. Gormfhlaith (who d. 947 after accidentally falling on her sharp-pointed bedpost), widow 1st of Cormac [K. of Munster] and 2nd of Cearbhall [K. of Leinster]; she was the daughter of his predecessor, FLANN SIONNA "the Fox" [K. of Ireland 876-916], head of the Southern Ui Neill. IT IS FROM THIS NIALL THAT THE O'NEILLS DIRECTLY DERIVE THEIR NAME.