Uí Dúnlainge also had to contend with the kings of
Osraige, whose power grew steadily in the late ninth
and tenth centuries. Cerball mac Dúngaile and his son
Diarmait mac Cerbaill, both kings of Osraige, allied
with Vikings and attempted to dominate Leinster. The
Uí Dúnlainge themselves quickly learned the advan-
tages of allying with Vikings; in 956 the Leinstermen
and Dublin Vikings killed the king of Tara. In the late
tenth century Dublin and its hinterland, though polit-
ically independent of Leinster, was seen as an impor-
tant center of wealth and power, and Irish kings,
including those of Uí Dúnlainge, attempted to assert
control of the settlement.
In the 980s and 990s, Uí Dúnlainge lost out as Brian
Boru attempted to control Leinster and Dublin as part
of his struggles with Máel-Sechnaill II for the high
kingship of Ireland. In 997, Máel-Sechnaill gave to
him the hostages of Leinster and Dublin he had pre-
viously held. The Laigin and Dublin Vikings were no
more amenable to the overlordship of Brian than to that
of the Uí Neill kings, and they rebelled in 999, to be
crushed by Brian. His success in Leinster was in part
due to the divisions between Uí Dúnlainge and Uí
Chennselaig, and between the branches of Uí Dún-
lainge themselves. In 1003, Brian deposed Donnchad
mac Domnaill of Uí Dúnchada as king of Leinster and
installed Máelmórda mac Murchada of Uí Fáeláin.
Brian was in fact married to Máelmórda’s sister,
Gormfhlaith (d. 1030), who had previously been mar-
ried both to Amlaíb Cuarán, king of Dublin, and to
Máel-Sechnaill. However, relations deteriorated over
the following years, and Máelmórda rebelled against
Brian. This culminated in the Battle of Clontarf in which
both were killed. The power of Osraige subsequently
grew again. Donnchad mac Gilla-Pátraic, king of
Osraige, intervened in Leinster several times, and in
1036 he took the kingship of the province. A fatal blow
had been dealt to declining Uí Dúnlainge power, and in
1042 the kingship of Leinster passed to Uí Chennselaig
in the person of Diarmait mac Máele-na-mBó.
Uí Dúnlainge retained considerable power in their
own districts into the twelfth century. Uí Dúnchada had
suffered territorially at the hands of the Dublin Vikings,
although they retained land at Lyon’s Hill and in the
area of the Dublin-Wicklow border. Their family name
at the time of the Anglo-Norman invasion was Mac Gilla
Mo-Cholmóc, and their descendants survived under the
new regime as the Fitzdermots. The English invaders
forced the Uí Fáeláin and Uí Muiredaig dynasties, at
that time represented by the families of Ua Brain
(O’Byrne) and Ua Tuathail (O’Toole) eastward into the
less fertile lands of the Wicklow Mountains. However,
they were able to survive and even prosper as Gaelic
lordships until the end of the Middle Ages.
M
ARK
Z
UMBUHL
References and Further Reading
Byrne, Francis J.
Irish Kings and High-Kings.
London: B. T.
Batsford, 1973.
Mac Shamhráin, Ailbe.
Church and Polity in Pre-Norman Ireland:
The Case of Glendalough.
Maynooth: An Sagart, 1996.
O’Byrne, Emmett.
War, Politics and the Irish of Leinster,
1156–1606.
Dublin: Four Courts Press, 2003.
Smyth, Alfred P.
Celtic Leinster. Towards an Historical Geog-
raphy of Early Irish Civilization
A
.
D. 500–1600
. Dublin: Irish
Academic Press, 1982.
See also
Anglo-Norman Invasion; Brian Boru;
Cerball mac Muireccáin; Diarmait mac
Máele-na-mbó; Dublin; Glendalough; Gormlaith
(d. 1030); Kildare; Laigin; Leinster; Máel-
Sechnaill; Uí Néill; Viking Incursions
UÍ MAINE, BOOK OF
The Book of Uí Maine is a fourteenth-century vernac-
ular Irish manuscript, part of which at least was written
for a member of the ruling family of Uí Maine,
Muirchertach Ua Ceallaig, bishop of Clonfert
(1378–1392), and later archbishop of Tuam (1392–1407),
as a colophon in the hand of one of its scribes, Fáelán
mac a’ Ghabann, makes clear. Fáelán is one of only
two scribes named in the codex, the second being the
principal redactor, Adhamh Cúisín, whose hand has
been identified on 99 of the Book’s 161 folios. As only
approximately 40 percent of the original codex has
survived, it is impossible to determine whether this
Anglo-Norman scribe was responsible for the greater
part of the manuscript in its pristine state, as William
O’Sullivan has remarked. As he was in Ua Ceallaig’s
employ when the latter was archbishop of Tuam,
however, his proximity to the patron of the work is not
in doubt. Moreover, as O’Sullivan’s analysis of the
various scripts has shown, he undertook his writing
later than all but one of the Book’s eight or so other
scribes, and thus may have overseen completion of
the work. Indicative of this perhaps is the fact that
he was also responsible for the preparation of the
manuscript for its first binding. Be that as it may,
Cúisín and his predecessors were followed by a number
of secondary scribes, the two principal hands of which
were at work in the sixteenth century. In the seven-
teenth century, as Nollaig Ó Muraíle has demon-
strated, our manuscript was known by the alternative
title,
Leabhar Uí Dhubhagáin
(“The Book of Ua
Dubagáin”), because of an association with the Uí
Dhubagáin who supplied hereditary poets to the
Uí Cheallaig. A number of texts attributed to the most
famous
ollam
(“chief poet”) of this family, Seáan
Mór Ua Dubagáin (d. 1372), are preserved in the
manuscript, and it has been speculated that a direct
descendant of his, Seáan son of Corbmac Ua DubagáinUÍ DÚNLAINGE