Mac Airt, Seán, and Gearóid Mac Niocaill, eds. The Annals of
Ulster (to A.D. 1131). Dublin: Dublin Institute for Advanced
Studies, 1983.
McCone, Kim. Pagan Past and Christian Present in Early Irish
Literature. Maynooth: An Sagart, 1990.
O’Grady, Standish H, ed. Silva Gadelica: A Collection of Tales
in Irish. London: Williams and Norgate, 1892.
Ó hÓgáin, Dáithí. Myth, Legend & Romance, an Encyclopaedia
of the Irish Folk Tradition. New York: Prentice Hall, 1991.
Ryan, Rev. John. Clonmacnois: A Historical Summary. Dublin:
Stationery Office, 1973.
See alsoAdomnán; Clonmacnoise; Colum Cille;
Uí Néill; Uí Neill, Southern
DIARMAIT MAC MÁELE-NA-MBÓ
(Reigned 1036–1072)
Diarmait mac Máele-na-mbó (died February 7, 1072
at Odba, Co. Meath) was king of the southeastern
kingdom of Uí Chennselaig and overlord of the prov-
ince of Leinster (1042–1072). Some medieval histori-
ans claimed that he was high king of Ireland, with
opposition (1063–1072). Diarmait's father Donnchad
mac Diarmata (fl. 1003) was more familiarly known
asMáel na mbó (the Cattle Rustler) and his mother
was Aífe, daughter of Gilla Pátraic mac Donnchada,
king of Osraige. Diarmait was one of the most pow-
erful Irish rulers of the eleventh century, as well as the
most internationally oriented of his contemporaries.
For almost a quarter century he controlled the wealthy
southeastern quarter of Ireland, while engaging in
adventures in England, the Isle of Man, and Wales.
The kingdom of Uí Chennselaig was located northwest
of Wexford, and by the eleventh century its capital was
at Ferns. Until the early eighth century it had provided
kings for the province of Leinster, but had been in
obscurity for the following three centuries. All this
changed in the course of Diarmait’s career. He became
king of Uí Chennselaig in 1036, after blinding a rival
named Ruaidrí mac Taidc. Diarmait understood that
the success of a prince depended very much on the
resources he commanded. Toward that end, he began
to bring the Viking towns of eastern Ireland under his
control. In 1037, Diarmait raided the Viking settlement
at Waterford.
Diarmait’s uncle Donnchad mac Gilla Pátraic, the
king of Osraige, had been recognized as king of Lein-
ster in 1036, but after his death in 1039 his family was
unable to maintain their hold on the province. Diarmait
began attacks on the new king, Murchad mac Dúnlainge
of the northern Leinster dynasty of Uí Muiredaig, and
in 1040 he raided the churches of Moone, Castledermot,
and Dunmanogue (all in Co. Kildare) in Murchad’s
territory. His successes emboldened Diarmait to
attempt to extend his authority throughout Leinster.
With his brother Domnall Remar (“the Fat”), Diarmait
raided the neighboring kingdom of Uí Bairrche. The
attempt was premature, however, and the brothers were
defeated in a battle at Kilmolappogue (Co. Carlow),
where Domnall was slain.
These activities alarmed Diarmait’s neighbors,
especially Donnchad mac Briain, the king of Munster
and claimant to the Irish high kingship. He was also
the father of Diarmait’s wife Derbforgaill (d. 1080),
and their son was Murchad (d. 1070). In 1041,
Donnchad burned Ferns, and in revenge Diarmait
attacked Killeshin (Co. Laois). Murchad, the king of
Leinster, was slain in 1042, and sometime thereafter
Diarmait was recognized as the provincial king of
Leinster. Nevertheless, Donnchad forced Diarmait to
surrender hostages (the customary sign of submission)
in 1048. Diarmait promptly demonstrated that his power
remained undiminished by leading a raid against the
Munster kingdom of Déisi and then, in alliance with
Niall mac Eochaid of Ulaid, overrunning Mide and
destroying its churches. The following year they were
raiding Brega.
Shortly after mid-century, there occurred two events
that changed Diarmait from a typical Irish prince to a
player on the international stage. In September 1051,
Diarmait provided refuge for two Anglo-Saxon nobles
named Harold and Leofwine Godwinson, who had
sailed from Bristol to Ireland. The brothers had been
forced to flee England as part of a power struggle
between their father and King Edward “the Confessor.”
They remained in Ireland for nine months before
returning to Britain in June 1052, with a fleet supplied
by Diarmait. With the successful reinstatement of the
Godwinsons in September, Diarmait now had powerful
friends in Britain. This led to increased trade between
southwest Britain and southeast Ireland. One aspect
was the slave trade that would be denounced by Bishop
Wulfstan II of Worcester.
An even more important event occurred in 1052,
when Diarmait captured the important Viking town of
Dublin. The little that is known of this triumph sug-
gests that it was intended to be a mere raid of Fine
Gall, but it escalated into the capture of the town after
its king, Echmarcach Rögnvaldsson (Mac Ragnaill),
fled. Diarmait placed his son Murchad in Dublin. Now
he controlled one of the wealthiest towns in the north-
ern Atlantic, which also had one of the most powerful
fleets. Using Dublin as a base, Diarmait raided the
lands to the north and west. A favored target was Mide,
whose rulers, the Southern Uí Néill dynasty of Clann
Cholmáin, had been politically ineffective since the
first quarter of the eleventh century. In 1053, his army
attacked Mide, and would raid it three more times:
1059, 1068, and 1072. Despite his increasing power,
he was again forced to submit to Donnchad mac Briain,
who raided Fine Gall in 1053.DIARMAIT MAC MÁELE-NA-MBÓ (Reigned 1036–1072)