Coscraig, whose ruling family were the Meic Áeda,
and the Muinter Murchada, whose ruling family were
the Uí Flaithbertaig. By the end of the eleventh century,
the Ua Flaithbertaig family were dominant within the
Uí Briúin Seóla and indeed managed to very briefly
take the provincial kingship in 1098 during the height
of dynastic instability within Connacht. In the mid-
thirteenth century, the Uí Flaithbertaig were deprived
of their possessions east of the Corrib by the de Burgh
family and moved west into present-day Connemara.
Common Uí Briúin Identity
Until the first half of the eleventh century, the various
Uí Briúin dynasties seemed to actively maintain some
sort of common Uí Briúin identity. Up until at least
the 1030s, there existed a title “king of Uí Briúin” that
was mostly bestowed upon the rulers of Uí Briúin
Seóla, functioning as subkings under the Ua Conchobair
kings of Connacht. Likely due to the dissension of the
eleventh century, however, the names of the constituent
elements of the dynasty thereafter proclaimed them-
selves to be much more discrete entities. Uí Briúin Aí
became known exclusively as Síl Muiredaig, while Uí
Briúin Seóla became known solely by the territorial
designation of Iar-Chonnacht. Only Uí Briúin Bréifne
retained the “Uí Briúin” element of their name, so much
so that by at least the beginning of the twelfth century,
the term Uí Briúin denoted Uí Briúin Bréifne alone.
ANNE CONNON
References and Further Reading
Byrne, Francis John. Irish Kings and High-Kings. London:
Batsford, 1973.
Duignan, M. V. “The Kingdom of Bréifne.” Royal Society of
Antiquaries of Ireland Journal65 (1935): 113–140.
Mac Niocaill, Gearóid. Ireland before the Vikings. Dublin: Gill
& Macmillan, 1972.
Ó Corráin, Donnchad. Ireland before the Normans. Dublin: Gill
& Macmillan, 1972.
Ó Mórdha, Eoghan. “The Uí Briúin Bréifni Genealogies and
the Origins of Bréifne.” Peritia16 (2002): 444–450.
Walsh, Rev. Paul. “Christian Kings of Connacht.” Journal of
Galway Archaelogical Society17 (1935): 124–142.
See alsoBurke; Connacht; Connachta;
Clonmacnoise; Leth Cuinn; Mide (Meath);
Niall Noígiallach; Tírechaán; Ua Conchobair;
Ua Conchobair, Ruaidrí; Ua Conchobair,
Tairrdelbach; Ua Ruairc; Uí Néill
UÍ CHENNSELAIG
Uí Chennselaig was one of the most important popu-
lation groups and dynasties in early medieval Leinster.
Uí Chennselaig considered themselves to be of the
Laigin and traced their descent to one Énna Cennselach
(“Énna the Dominant”), a grandson of Bressal Bélach,
the ancestor also of Uí Dúnlainge. It is probable that
Uí Chennselaig originally came from the Barrow val-
ley and moved eastward into central Leinster, where
their early royal center was Ráth Bilech (Rathvilly, Co.
Carlow); later they expanded southward across the
Blackstairs Mountains into the fertile plains of County
Wexford and won supremacy in the south of the prov-
ince, so that their rulers were occasionally styled rí
Laigin Desgabair (“king of south Leinster”) in the
annals.
The first significant Uí Chennselaig king was
Brandub mac Echach (d. 605) who defended Leinster
against Uí Néill encroachments. Despite this success,
Brandub’s branch of the dynasty, Uí Felmeda of Ráth
Bilech, were unable to compete with Uí Dúnlainge of
north Leinster, and their power was eclipsed. In the eighth
century, members of Síl Cormaic and Síl Máeluidir
competed for the Uí Chennselaig kingship. Some of
them also became kings of Leinster, but after 738 Uí
Dúnlainge excluded the other Laigin dynasties from
the provincial kingship for over three hundred years.
Accordingly, Uí Chennselaig set about consolidating
their hold on south Leinster: Síl Cormaic expanded
into the territories of Uí Dróna (south Co. Carlow) and
the area around the church of St. Mullins on the Barrow
with which Uí Chennselaig had long-standing associ-
ations; Síl Máeluidir had meanwhile taken control of
the lower Slaney and the area adjacent to Wexford
harbor, in the process isolating earlier Leinster peo-
ples, Uí Bairrche and Fothairt.
In the ninth century, Uí Chennselaig power was
centered on the church of Ferna Mór Máedóc (Ferns,
Co. Wexford). Uí Chennselaig had close associations
with the church, and several members of the dynasty
also held ecclesiastical office there, sometimes in com-
bination with the kingship; Cathal mac Dúnlainge is
titled rex nepotum Cennselaig et secnap Fernann
(“king of Uí Chennselaig and prior of Ferns”) in the
annals at his death in 819. During this period, Viking
incursions in south Leinster led other churches to look
increasingly to the protection and patronage of Uí
Chennselaig kings, and so the annals report Cairpre
mac Cathail fighting with the muinter(“community”)
of the church of Tech Munnu (Taghmon, Co. Wexford)
against Vikings in 828. Viking activities had an
increasing effect on the intradynastic struggles of Uí
Chennselaig, particularly after the establishment
of Viking settlements at Wexford and Waterford.
From the late ninth century, branches of the
dynasty including Síl Cormaic, Síl nÉladaig, and
Síl nOnchon were all contenders for the overall
kingship. Síl nOnchon, originally an obscure
group, provided two kings of Uí Chennselaig inUÍ BRIÚIN