UA BRIAIN, MUIRCHERTACH (1050–1119)in any case, to mount an effective nationwide resis-
tance to the English. Nonetheless, Ua Briain hostility
toward the colonists in Thomond continued unabated,
and there was widespread devastation in the border-
lands around Bunratty and Limerick.
In a bid to overcome the determined opposition of
Ua Briain, Edward I granted all of the Ua Briain
lordship to Thomas de Clare, brother to the king’s
chief adviser, the earl of Gloucester. De Clare made
some kind of agreement with Brian Ruad Ua Briain,
the king of Thomond, but treacherously killed Ua
Briain in 1277. Brian Ruad’s sons prevented de Clare
from taking immediate advantage of their father’s
murder. However, Thomond was without a strong
leader, and internecine rivalry among the Uí Briain
allowed de Clare to force the next king of Thomond,
Tairrdelbach Ua Briain, into an arrangement whereby
he agreed to hold all of Thomond beyond Bunratty
for an annual rent of £120. Following his death, there
was further internecine strife among the Uí Briain
which was exploited by Richard de Clare. De Clare
sought to extend his sway across County Clare, but
at the battle at Dysert O’Dea in 1317 de Clare was
killed by forces led by Muirchertach Ua Briain, a son
of Tairrdelbach Ua Briain. The threat from the de
Clares was ended and the Uí Briain’s control of
Thomond was assured. The battle at Dysert proved to
be a decisive encounter.
The Uí Briain Revival
After Dysert O’Dea, the Uí Briain went on the offen-
sive against the English colonists. The colony at
Bunratty was put under sustained pressure and fell to
the Irish in the 1350s. The frontiers of Ó Briain power
were pushed right up to the walls of Limerick. There
were repeated raids east of the Shannon to harass the
English lordships in Ormond. In 1370, Brian Sreamhach
Ua Briain, king of Thomond, won a great victory
against the earl of Desmond south of the Shannon. His
subordinates captured and sacked the city of Limerick.
Such audacity, however, prompted the intervention of
the English chief governor, Sir William de Windsor,
and an uneasy modus vivendi was established between
Ua Briain and the embattled English colonists. Limerick
was restored to English control, but Ua Briain was in
the ascendant.
In 1466, Tadc Ua Briain, lord of Thomond, led an
army across the Shannon and imposed his overlord-
ship over the MacBriens of Coonagh and Aherlow
and the Clanwilliam Burkes. He imposed a “black
rent” on the inhabitants of Limerick city and the east
of County Limerick, a financial tribute reflecting his
military power. At the close of the Middle Ages, the
Uí Briain were again one of the most powerful dynas-
ties in Ireland.Conclusion
It has to be conceded that the Uí Briain were fortunate
in that their heartlands, in modern County Clare, were
relatively remote from England and accordingly less
attractive to English colonists. Also, their core territory
had the advantage of geographical cohesion, bounded
as it was by the Shannon river and estuary, the Atlantic
Ocean, and the lordship of the Gaelicized Clanrickard
Burkes with whom they maintained good relations.
Nonetheless, the survival of the Ó Briain lordship in
the later Middle Ages was due primarily to the tenacity
and resourcefulness of its leaders. Their grasp of real-
politik, and their readiness to seek and maintain
accommodations with the English while offering stiff
resistance to incursions west of the Shannon, helped
them to come through the most threatening phase of
English colonization up to 1317. Their firm gover-
nance and control of their subordinates within
Thomond gave them the strength to take advantage of
English weaknesses subsequently so that they became
a force to be reckoned with across much of the territory
of the former kingdom of Thomond. That strength and
adaptability was demonstrated again in 1542 when
Muirchertach Ua Briain became the first earl of
Thomond under the auspices of Henry VIII’s policy
known as “surrender and regrant.” The earldom was a
recognition of Ua Briain’s stature as one of the most
important lords in Ireland.
HENRYA. JEFFERIESReferences and Further Reading
Byrne, Francis. Irish Kings and High-Kings. London, 1973.
Duffy, Seán. Ireland in the Middle Ages. Dublin, 1997.
Nicholls, Kenneth. Gaelic and Gaelicised Ireland in the Later
Middle Ages. Dublin, 1972.
See alsoBrian Boru; Dál Cais; Eóganachta;
Munster; Ua Briain, Muirchertach;
Ua Briain, TairrdelbachUA BRIAIN, MUIRCHERTACH
(1050–1119)
Muirchertach Ua Briain (1050–1119) was the son of
Tairrdelbach (d. 1086), son of Tadc (d. 1023), son of
Brian Boru, the latter’s most successful successor as
king of Dál Cais, Munster, and Ireland. The Annals of
Tigernach (perhaps anachronistically) record his birth
in 1050, and he otherwise appears on record only in
1075 when his father led the armies of Munster, Leinster,