VIKING INCURSIONSattacks, Irish armies began to intercept the raiders, with
varying degrees of success, from the 810s. By the 820s,
Viking fleets had circumnavigated Ireland (for exam-
ple, raiding Skellig Michael in 823). The long distance
of some of these campaigns from Scandinavia has led
some commentators to suggest that the first raiders
came from colonies in the Northern and Western Isles
of Scotland.
Initially, Vikings seem to have been motivated by
desire for portable wealth in the form of tribute, stolen
goods (including reliquaries—the contents were some-
times discarded), and slaves. Some of the loot made
its way back to Scandinavia, as demonstrated by finds
of insular metalwork in Norwegian graves.
In the 830s and 840s, Vikings made more strenuous
efforts to establish a foothold in Ireland. Numerous
bases, sometimes called longphoirt(ship ports), were
founded. The earliest recorded examples are Arklow
(836), Lough Neagh (839), and Dublin and Annagassan
(841). At the same time Viking campaigns extended
further inland, exploiting the major river systems of
Ireland. The bases enabled booty to be ransomed or
traded locally, and they fostered closer interaction
between Vikings and the Irish. Many bases were tem-
porary, but others, notably Dublin, Limerick, and
Waterford, have been occupied ever since.
A number of Irish kings used this new turn of events
to their advantage by recruiting Viking support against
their enemies. Alliances between Vikings and Irish, such
as that involving the Osraige king Cerball mac Dúngaile,
are well attested from the mid-ninth century. In conse-
quence, the reasons behind Viking incursions became
more sophisticated, combining desire for booty with
political strategy. Of the native rulers who sought to
block Viking expansion in Ireland, Máel-Sechnaill, son
of Máel-ruanaid, achieved particular success.
It is evident that a number of different Viking armies
operated in Ireland. During the 850s, three major
groups jostled for power:Finngaill(Fair Foreigners),
Dubgaill(Dark Foreigners), and Gall-Goídel(Foreign-
Gaels). The Dark Foreigners were ultimately success-
ful under the leadership of Ívarr (who died in 873) and
his descendants, who were based in Dublin.
During the late ninth century there was a decrease
in recorded attacks in Ireland, which may be linked
with the activities of Ívarr and his associates in Britain.
In 866 and 867, Ívarr’s absence encouraged Irish rulers
to destroy a number of Viking bases. After a resurgence
of Viking attacks in Ireland in the late 870s and 880s,
the power of Ívarr’s descendants was compromised by
dynastic infighting. This led to the expulsion of leading
Vikings from Dublin in 902 by a coalition of troops
from Leinster and Brega. The exile of the dynasty of
Ívarr lasted until 914. In the interim, there is scant
record of Viking activity in Ireland, while Cerball mac
Muirecáin, who had ousted the Viking leaders from
Dublin, died in 909.
After the restoration of the dynasty of Ívarr, there
was a period of vigorous Viking activity that lasted
until the 940s. These years perhaps mark the zenith of
Viking power in Ireland. Recurrent attacks were led
against Irish power centers such as Armagh and
Clonmacnoise. There was also fierce competition
between the Viking settlements of Dublin and Limerick.
Numerous Viking bases were established across Ireland
in these years as the rival groups sought to extend their
sphere of influence. These incursions were curtailed
in 937, when the Vikings of Limerick were crushed by
their Dublin rivals, and in the 940s by defeats inflicted
on Dublin by Congalach, over king of Brega.
In the late tenth century, Viking settlements increas-
ingly fell under the influence of Irish rulers. Not only
did Viking incursions decrease in number, but their
actions became less autonomous. Brian Boru brought
Waterford, Limerick, and (temporarily) Dublin under his
control before his death at the battle of Clontarf in 1014.
From that time, ambitious Irish over kings vied for
control of the wealth and military resources of Dublin,
which was the premier town of Ireland. Viking armies
increasingly acted under the direction of Irish leaders.
Nevertheless, the Viking dynasty of Ívarr still remained
influential in Dublin. A branch of the dynasty, which
ruled the Hebrides and Man, also continued to inter-
vene in Irish affairs. In 1091, 1142, and perhaps in
1162, Viking kings of the Isles seized control of Dublin.
After Magnús, king of Norway, took control of the
Isles in 1098, he also intruded in Irish politics. He was
killed on a raid in Ulster in 1103, and his alleged son
from an Irish or Hebridean lover went on to rule Norway.
Thus, for an extended period, the kingdom of the Isles
was closely linked with Viking activity in Ireland.
The Viking Age in Ireland ended in the 1170s when
the English seized control of the Hiberno-Scandinavian
towns. In a final gasp for power, Ascall, the deposed
ruler of Dublin, led a contingent from Man and the
Isles against the town in 1171, but he was captured
and beheaded. The term gall(foreigner), most fre-
quently applied by Irish chroniclers to the Vikings, was
soon after transferred to the English.
Viking incursions had a significant impact on Irish
history. To them, past scholars have attributed both the
decline of Uí Néill as over kings of Ireland and the
increasing lay control of churches—although such
views have since been modified. In the economic
sphere, Vikings stimulated trade through their network
of external contacts. They founded towns and intro-
duced coinage. Irish rulers adopted Viking military
techniques, and Vikings also made their mark on IrishVIKING INCURSIONS