Murkertac of the Leather Cloaks, King of Ailech and Ulster 938 to 943.
Niall was succeeded in the sovereignty of Ulster by his nephew Fergal, son of Donal, Murkertac his son not being of age.
Murkertac soon came to the fore, however, and was the real King of Ulster during the seventeen years that his cousin held the title, judging from the records of the two. Murkertac spent nearly his whole life in battling against the Danes, proving himself the most formidable enemy they had yet encountered in Ireland.
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 Keenagh, he was caught offguard by the Norse in his own fortress of Ailech in 939, and was taken as a prison 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 Cinel Eoghain.
They wore leather cloaks to protect against the winter cold, they carried of local kings in chains, feasting them royally at Ailech, and then sending them as hostages to his father in-law, the High King.
Muircheartach was killed in battle against Biacar ( K. of Dublin ) in March 943. He was married to Flann, daughter of Donchada ( K. of Ireland 919 to 944 ) head of the southern Néill.
Muircheartach was married a second time to Dubhdara, daughter of Ceallach ( K. of Ossory ) . By Flann he had with other issue two sons and a daughter:
(1) Flaithbertach ( K. of Ailech ) who was killed 949 defending his lands against a raid by the Cinel Conall.
(2) Domnall Ardmacha ( of Armagh ) K. of Ireland
(3) Donnfhlaith his daughter who married Donmall ( K. of Meath ) head of the southern Néill.
She married a second time to Olaf Cuaran" ( Hairy-Breeches ) K. of Northumberland also K. of Dublin.