not until the ninth and tenth centuries, during the
reigns of Máel-Sechnaill I mac Máele-ruanaid (d. 862),
and a number of his successors, that the Uí Néill
achieved anything approaching dominance over the
entire country.
The rise of the Uí Néill to prominence, and the
subsequent maintenance of that dominance, owed
much to their relationship with the church. From the
seventh century onward, they were closely allied to
Armagh, which was at that time asserting its own
claims to primacy over the church in Ireland. Branches
of the Uí Néill also had close associations with the
various churches of the Columban federation; St.
Colum Cille (d. 597), belonged to Cenél Conaill of the
Northern Uí Néill. Later, the Uí Néill, and especially
the Clann Cholmáin, were to forge strong links to the
major monastic foundation of Clonmacnoise, where a
number of the antiquities from the tenth and eleventh
centuries bear testimony to the close association
between church and dynasty.
The decline of the Uí Néill dynasty in the late tenth
century was due in large measure to the emergence of
the Dál Cais dynasty in Munster—a dynasty which under
Brian Bóruma (d. 1014), his grandson Tairrdelbach
(d. 1086), and his great-grandson, Muirchertach Ua
Briain (d. 1119) demonstrated the ambition and vigor
to lay claim to the overlordship of Ireland.
P
AUL
B
YRNE
References and Further Reading
Byrne, Francis John. “The Rise of the Uí Néill and the High-
Kingship of Ireland.” O’Donnell Lecture. Maynooth:
National University of Ireland, 1969.
Byrne, Francis John.
Irish Kings and High-Kings
. London:
Batsford, 1973. Reprint, Dublin: Four Courts Press, 2001.
Byrne, Paul. “Certain Southern Uí Néill Kingdoms (Sixth to
Eleventh Century).” PhD diss., University College Dublin,
2000.
Kelleher, J. V. “The Rise of the Dál Cais.” In
North Munster
Studies: Essays in Commemoration of Monsignor Michael
Moloney
, edited by Etienne Rynne, pp. 230–241. Limerick:
The Thomond Archaeological Society, 1967.
Mac Shamhráin, Ailbhe. “Nebulae discutiuntur? The Emer-
gence of Clann Cholmáin, Sixth–Eighth Centuries.” In
Seanchas: Studies in Early and Medieval Irish Archaeology,
History and Literature in Honour of Francis J. Byrne
, edited
by Alfred P. Smyth, pp. 83–97. Dublin: Four Courts Press,
2000.
O’Rahilly, T. F.
Early Irish History and Mythology
. Dublin:
Dublin Institute for Advanced Studies, 1946.
See also
Armagh; Clonmacnois; Colum
Cille; Connachta; Dál Cais; Diarmait mac
Cerbaill; Leth Cuinn; Lóegaire mac Néill;
Máel Sechnaill I; Máel Sechnaill II; Mide;
Niall Nóigiallach; Tara; Uí Néill, Northern;
Uí Néill, Southern
UÍ NÉILL, NORTHERNThe Early Period—Cenél Conaill
Dominance
“The Northern Uí Néill” is the collective name for
the dynasties established in northwest Ulster by
Eógan, Conall, and Éndae, three putative sons of Niall
Noígiallach, known respectively as Cenél nEógain,
Cenél Conaill, and Cenél nÉnnai. If Cenél nÉnnai
ever held a prominent position, it has left no trace in
the historical records, and the history of the Northern
Uí Néill is, essentially, the history of Cenél Conaill
and Cenél nEógain.
From the sixth century, when the Northern Uí Néill
emerged onto the pages of history, until the latter half of
the eighth century, Cenél Conaill were the dominant
grouping among the Northern Uí Néill. However, the
standing of Cenél nÉogain was by no means insignificant
during this period, in the course of which several mem-
bers of that dynasty attained the over kingship of the Uí
Néill. At the battle of Mag Roth (Moira, Co. Down) in
637, Domnall mac Áedo of Cenél Conaill, who styled
himself
rex Hibernie
(“king of Ireland”), defeated an
alliance of the king of Ulaid and the Dál Riata from
Scotland. After this battle, the Uí Néill were established
as the dominant power in the north of Ireland. The base
of Cenél Conaill and Cenél nEógain lay in the relatively
poor lands of Donegal in the northwest of Ireland (the
massive stone fortress of Ailech, in the Inishowen
peninsula, was to remain synonymous with the kingship
of Cenél nEógain long after the center of Cenél nEógain
power had moved to the east). Between the Northern Uí
Néill and the Ulaid (largely confined to counties Antrim
and Down) lay the extensive lands of the Airgialla
(“those who give hostages”), a group that increasingly
fell under the sway of the Northern Uí Néill.The Emergence of Cenél nEógain
Flaithbertach mac Loingsech, who abdicated the over
kingship of the Uí Néill in 734, having been challenged
by Áed Allán of Cenél nEógain, was the last Cenél
Conaill dynast to attain that status. The reign of Áed
witnessed the beginning of the arrangement, which was
maintained for two and a half centuries (with only one
exception), whereby the kingship of the Uí Néill alter-
nated between the Cenél nEógain and the Clann
Cholmáin of the Southern Uí Néill. The battle of
Clóitech in 789, in which the Cenél Conaill were
roundly defeated by Cenél nEógain, seems to have con-
solidated the already superior status of the latter dynasty.
Cenél nEógain expansion from their northeast
Donegal base into Derry, Tyrone, and Fermanagh wasUÍ NÉILL