Uí Néill High Kings

The Uí Néill were descended from the protohistoric Niall Noígiallach, who may have been a real person; however, the way the genealogists and saga writers depict his ancestors and the relationships among his descendents is schematic and unhistorical. Diarmait mac Cerbaill, his grandson (d. 565), was an ancestor of the Southern Uí Néill, who were based in Meath and the east midlands. These divided into two hostile branches, Síl nAeda Sláine and Clann Cholmáin. The real establishment of Uí Néill power in the midlands may have been the work of Áed Sláne (d. 604) and his immediate successors, who provided some eight overkings of Uí Néill. Their rivals to the west, Clann Cholmáin (descendents of Áed Sláne's brother, Colmán Már, in the genealogies) became over-kings of Uí Néill only in 743, and thereafter, with one exception, that of Congalach Cnogba (944–956), completely excluded their cousins from that office. Other branches of the Uí Néill of the midlands, if they ever held the overkingship, were soon excluded and survived as the political subordinates of their kinsmen.

Niall is also represented as father of Conall and Eógan, ancestors of Cenél Conaill and Cenél Eogain, the dominant dynasties in the northwest, known collectively as Northern Uí Néill. Cenél Conaill was more powerful than Cenél Eogain from the late sixth to the mid-seventh centuries. Two Cenél Conaill overkings of Uí Néill, Domnall mac Áeda (d. 642) and Longsech mac Óengusso (d. 704), are called rex Hiberniae (king of Ireland) in the annals. The last of their kings to hold the overkingship, Flaithbertach mac Longsig, abdicated in 734. After 789 Cenél Eogain dominated the north and expanded slowly southeastwards over central Ulster and eventually got control of County Armagh.

From the 840s the overkingship of Uí Néill, usually called the kingship of Tara, alternated regularly between Clann Cholmáin in the south and Cenél Eogain in the north. The overking of Uí Néill was usually the most powerful king in Ireland, and claimed to be king of Ireland—a claim realized for a period by Mael Sechnaill mac Mael Ruanaid (846–862). The meteoric rise of Brian Boru, king of Munster (978–1014) and king of Ireland (1002–1014), broke the Uí Néill supremacy and began an intense and violent struggle between powerful provincial kings for the kingship of Ireland, a struggle in which the northern Uí Néill remained key players.

SEE ALSO Dál Cais and Brian Boru; Norse Settlement; O'Connors of Connacht

Bibliography

Bhreathnach, Edel. "Temoria: Caput Scotorum?" Ériu 47 (1996): 67–88.

Byrne, Francis John. The Rise of the Uí Néill and the High-Kingship of Ireland. 1970.

Byrne, Francis John. Irish Kings and High-Kings. 1973.

Donnchadh Ó Corráin