toHenry VIII of England. The O’Byrnes had lands in
the southern Wicklow Mountains and in Críoch Branach
(O’Byrne Territory) on the coast. They too fought
against the English and other Gaelic lords, but by the
later sixteenth century the coastal areas were largely
in the orbit of the colonial administration. One branch
of the family, the lords of Críoch Raghnall (Raghnall’s
Territory) in the Wicklow Mountains, resisted the
English to the end of the sixteenth century, notably in
the person of Fiach Ua Brain, whose death in 1597
heralded the end of Gaelic Leinster.
MARK ZUMBUHL
References and Further Reading
Byrne, Francis J. Irish Kings and High-kings. London: B.T.
Batsford, 1973.
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 alsoAnglo-Norman invasion; Diarmait mac
máele-na-mbó; Dublin; historical tales; Laigin;
MacMurchada, Diarmait; MacMurchada
(MacMurrough) family; Mide; Uí Chennselaig;
Uí Dúnlainge; Uí Néill; Viking incursions
LEINSTER , BOOK OF
History
TheBook of Leinster is one of the foremost manu-
scripts of the twelfth century following Lebor na
hUidhre. Its modern name derives from its large con-
tent of Leinster-based texts, genealogies, and saga
material, but the title Leabhar Laighneachis usually
reserved for the collection of Leinster genealogies. It
is now housed in the library at Trinity College, Dublin,
Ireland, with the shelf number H 2 18, 1339. It has
mistakenly been called The Book of Glendalough, but
it is recognized as Leabhar na Nuachongbála (the
book of the New Foundation), identified as the town-
landNuachongbáil, Oughavall, near Stradbally in
County Laois.
The territory had belonged to the Uí Chrimthainn,
a member of whose family was the principal scribe of
the manuscript. The patron may have been Diarmait
Mac Murchada, who had one of his strongholds in Dún
Máscclose to An Nuachongbáil. In the twelfth century,
the Uí Chrimthainn had become an ecclesiastical family
and the land passed into the control of the Uí Mhórda
(O’Moores).Dún Máscpassed from Diarmait to his
daughter’s husband, Strongbow. From him the land
passed to his daughter Isabel and then as part of her
dowry to the Marshal Earls of Pembroke and to their
descendants. Meiler fitz Henry exchanged some of his
land in Kildare for property in Laois and reestablished
an Augustinian monastery, and gave the monastery all
the churches on his estate. Oughavall passed into the
ownership of the priory.
The manuscript reappears in the fourteenth century
at Oughavall and may have been kept in the vicarage
meanwhile. There is an entry in the margin that says
the book was in the possession of Calbach Ó Mórdha
in 1583 and that it is on loan to Seán Ó Ceirín. It is
noted elsewhere that it was in the possession of Ruaidhrí
Ó Mórdha, Calbach’s son, at a later date. There are two
further connections with the Ó Mórdha family, a
panygeric to the Clann Domnaill that included the
Ó Mórdha family and a faded note referring to Conall
son of David Ó Mórdha restoring the castle at Dún Másc.
If the manuscript was held at the vicarage, this
would explain the later Anglo-Norman additions by
scribes who used Latin and English script. These date
from the early fourteenth century to those of poems
written in the fifteenth century and include Pope
Adrian’s Laudabiliter, the papal bull that sanctioned
the Anglo-Norman invasion two hundred years before.
W.O’Sullivan dates the foliation and rebinding to
this period and maintains that the newly found
manuscript was a highly prized possession. The cas-
tle at Dún Máscwas burnt in 1324 and rebuilt by the
Ó Mórdha family, and there is a praise poem to a
Melaghlin Ó Mórdha, who died in 1502, on one of the
pages.
It was loaned to various scholars, and when the
binding disintegrated, separate parts were borrowed by
antiquarians. The Franciscans had a section in their
church in Donegal, but the Ó Mórdha family kept the
main manuscript, which they took with them to Ballyna
in County Kildare when they lost their lands in County
Laois. Sir James Ware made a note of its existence
there. In 1700, the Welsh archaeologist Edward Lhuyd
bought the manuscript during a tour of Ireland. He
collected many Irish manuscripts, including the Yellow
Book of Lecan, and he made a habit of binding them
together badly. But he did little to interfere with the Book
of Leinster, apart from making notes on the foliation.
The book was bought by Sir Thomas Saunders
Sebright after Lhuyd’s death, and it was presented to
Trinity College in 1782 by Sebright’s son; it eventually
reached the College in 1786. There was no effort to
collate or bind the manuscript until 1841, when
O’Curry was given the task of providing an index and
rearranging the leaves. At this time it was boxed for
the first time and referred to as H.2.18.
O’Sullivan says that the material is carefully
divided into different sections, but that there are certainLEINSTER