[K. of Aileach 938-43, Royal Heir of Ireland], called "the Hector of the Western World," was one of the greatest of Irish military commanders, and was known by his long yellow hair. Though generous to his enemies, he often defeated the Danes and Norsemen and overran the region around Dublin; in 927 he defeated and killed Goach, the rebellious local king of Keenaght. He was caught offguard by the Norse in his own fortress of Aileach in 939, and was taken as a prisoner to their ships on Lough Swilly, but escaped; he fitted out his own fleet and pursued the Norse to their base in the Hebrides, which he plundered in 941. He then made his famous Circuit of Ireland in midwinter of that year with a picked force of the Cenel Eogan (wearing leather cloaks against the cold), carrying off the local kings in chains, feasting them royally at Aileach, and them sending them as hostages to his father-in-law, the High King. Muircheartach was killed in battle against Blacar [K. of Dublin] in Mar 943. He married Flann (who d. 940), daughter of Donchadh [K. of Ireland 919-44], head of the Southern Ui Neill. He married in 941 Dubhdara, daughter of Ceallach [K. of Ossory].