UÍ NÉILL, SOUTHERNat the expense of the Airgialla. So extensive was this
expansion that, by the ninth century, Airgialla had been
restricted to the southeast of the modern province of
Ulster. Sometime during this period of expansion,
Cenél nEógain established their inauguration site at
Tulach Óc (Tullaghogue) in county Tyrone. The
descendants of the Cenél nEógain kings, the O Néill
family of Tyrone, were inaugurated standing on the
“Stone of the Kings” at Tullaghogue until 1602 when
the stone was smashed by Lord Mountjoy.
Following their defeat at the hands of Niall Caille
mac Áedo of Cenél nEógain at the battle of Leth Cam
near Armagh in 827, the Airgialla became a subject
people of the Northern Uí Néill. Of even greater sig-
nificance was the fact that, after Leth Cam, the abbacy
of the church of Armagh also fell under the effective
control of Cenél nEógain—a control that they exer-
cised through the Airthir, a branch of Airgialla settled
near Armagh. So close were the ties between Cenél
nEógain and Armagh that Áed Findliath, the Cenél
nEógain king of Tara, had his own house there in 870.
A century later, Domnall Ua Néill, a great-grandson
of Áed, whom the annalists styled
ardrí Érenn
(“High
King of Ireland”), died after penance in Armagh.
The tenth century in Ireland witnessed renewed
Viking incursions. Among the most effective Irish kings
at dealing with the enhanced Norse presence was the
Cenél nEógain king, Muirchertach na Cochall Craicinn
(“of the Leather Cloaks”) mac Néill, who defeated the
Vikings near Armagh in 921 and at Carlingford and
Annaghassan in 926. He slew the jarl Torulb in 932,
defeated the combined forces of the king of the Ulaid
and the foreigners in 933, and launched a successful
onslaught, in conjunction with Donnchad Donn, the
Clann Cholmáin, over king of the Uí Néill, against the
Dublin Norse in 938. Not surprisingly, he met his death
at the hands of the Norse in 943.
The Northern Uí Néill During
the Eleventh and Twelfth Centuries
Domnall ua Néill (d. 980), son of Muirchertach of the
Leather Cloaks, was the last king of Cenél nEógain
for over a century to assume a position of national
dominance. In the period following Domnall’s reign,
the Ua Briain dynasty of Dál Cais in Munster suc-
ceeded in excluding all branches of the Uí Néill from
political power on the national stage. However, the
emergence of Domnall Ua Lochlainn in the late elev-
enth century represented something of a revival in the
fortunes of Cenél nEógain. At various stages in his
career, he achieved dominance over, among others, the
Ulaid, Cenél Conaill, and Uí Máelsechlainn of Clann
Cholmáin. The submission of Muirchertach Ua Briain
to Domnall in 1090 was short-lived, and he was to
continue to oppose Domnall. Domnall’s successes,
such as they were, were due in no small part to the
support that he received from the church of Armagh.
The annalists, recording Domnall’s death in 1121,
accord him the title
ardrí Érenn
—a designation
scarcely matched by the evidence. The achievements
of Domnall’s grandson, Muirchertach Mac Lochlainn,
between the middle 1140s and his death in 1166, were
more substantial. Following a series of successful mil-
itary campaigns, Muirchertach had become the fore-
most dynast in the country by the early 1150s. His
position was, however, never secure and was continu-
ally challenged by Tairrdelbach Ua Conchobair of
Connacht and his son Ruaidrí. However, in 1161, Mac
Lochlainn secured the submission of all the principal
kings of Ireland, including Ruaidrí Ua Conchobair. By
1166, Muirchertach was facing a rebellion of Ruaidrí
Ua Conchobair, who had the support of most of the
major Irish kings, and the backing of Muirchertach’s
enemies within Cenél nEógain. Muirchertach died in
1166 as he prepared to confront Ua Conchobair’s
invading army. The annalists called him
rí Érenn
—a
dignity that was certainly not universally recognized
at the time of his death.
P
AUL
B
YRNEReferences and Further Reading
Byrne, Francis John.
Irish Kings and High-Kings. London:
Batsford, 1973. Reprint, Dublin: Four Courts Press, 2001.
MacShamhráin, Ailbhe. “Cenél nEógain and the Airgialla from
the Sixth to the Eleventh Centuries.” In
Tyrone: History and
Society
, edited by C. Dillon and H. J. Jefferies, pp. 55–84.
Dublin: Geography Publications, 2000.
Ó Corráin, Donnchadh.
Ireland before the Normans
. Dublin:
Gill and MacMillan, 1972.
Ó Fiaich, An tAth Tomás. “The Church of Armagh Under Lay
Control.”
Seanchas Ard Mhacha: Journal of the Armagh
Diocesan Historical Society
5, no. 1 (1969): 75–127.
Simms, Katharine. “Late Medieval Tír Eoghain: The Kingdom
of the Great Ó Néill.” In
Tyrone: History and Society
, edited
by C. Dillon and H. J. Jefferies, pp. 127–162. Dublin: Geog-
raphy Publications, 2000.
See also
Ailech; Airgialla; Armagh; Dál Cais;
Inauguration Sites; Mac Lochlainn; Niall
Noígiallach; Ua Néill family; Uí Néill; Uí Néill,
Southern; Ulaid; Viking Incursions
UÍ NÉILL, SOUTHERNBackground and Early Period
“The Southern Uí Néill” is little more than a conve-
nient designation for the several branches of the Uí
Néill that occupied territories stretching across the