Battle of Clontarf Summary

  • Last updated on November 11, 2022

The Battle of Clontarf pitted the Irish forces of Leinster and their Norse allies against the Munster forces of Brian, resulting in Brian’s victory on Good Friday and the dismantling of Norse control in Ireland.

Summary of Event

Few battles in Irish history command the fame that has been attached to Brian’ Brian (king of Ireland) victory at Clontarf on Good Friday, April 23, 1014. Since medieval times, the Battle of Clontarf has been presented as a struggle between Irish forces and Norse invaders for the control of Ireland. Correspondingly, the Irish victory has been seen as breaking the power of the Norse in Ireland Ireland;Vikings and and as a defining moment in Ireland’s progress toward national unity under a single king. Moreover, the fact that Brian, a Christian king, was killed by a pagan Norseman on Good Friday, the day of Christ’s death, made for suitable hagiographical comparisons. Most of these claims belong to legend rather than history, however, and originated in a propagandistic Irish work, entitled Cogadh Gaedhel re Gallaibh (c. 1100; The War of the Gaedhil with the Gaill, 1867), War of the Gaedhil with the Gail, The that was designed to glorify Brian. [kw]Battle of Clontarf (April 23, 1014) [kw]Clontarf, Battle of (April 23, 1014) Clontarf, Battle of (1014) Ireland;Apr. 23, 1014: Battle of Clontarf[1530] Expansion and land acquisition;Apr. 23, 1014: Battle of Clontarf[1530] Wars, uprisings, and civil unrest;Apr. 23, 1014: Battle of Clontarf[1530] Brian Murchad Sitric Mac-Aulaffe I Brodar Ospak Sigurd

For a more objective and reliable account of what happened, the primary source is the Annals of Ulster Annals of Ulster , a year-by-year chronicle, started in 431 and completed in 1541, of Irish events, whose entry on the battle may be almost contemporaneous. Not only does it detail the military movements in the preceding months, but it also lists the main contestants and fatalities in the battle. Curiously, the Annals of Inisfallen Annals of Inisfallen (c. 1015 to c. 1318), the chronicle that originated in Munster (the province from which Brian hailed) and might have been expected to provide the fullest and most detailed account, is disappointing on both counts. Next in importance to the annals as a source is The War of the Gaedhil with the Gaill. This work, composed during the reign of Brian’s great-grandson, was designed to glorify Brian. It is cast in the form of a native saga with heroes and villains, contains much dramatic incident, and is written in a suitably hyperbolic style. Obviously, its propagandistic intent, coupled with its adherence to the conventions of a literary genre, make it suspect as a historical source. At best, it can be described as a “tale with a historical background.”

Even more unreliable are the various versions of the Middle Irish saga Cath Cluana Tarbh (eleventh century; The Battle of Clontarf, 1832), Battle of Clontarf, The which, among other marvels, has supernatural figures visiting the protagonists before the battle. Yet, if nothing else, these tales bear witness to the extraordinary importance later assumed by the battle among the literate classes in Ireland. A final source is Njáls Saga (c. thirteenth century; The Story of Burnt Njal, 1861), Story of Burnt Njal, The the most famous of the Icelandic prose sagas, which was probably composed in the thirteenth century. While attesting that the reverberations of the Battle of Clontarf were also felt in the Scandinavian world, this source provides a unique Norse perspective on events. Although its account of the battle is dull, it does provide details about the Norse combatants that may well be genuine.

Brian belonged to the Dál Cais Dál Cais , a minor tribe occupying an area of southwest Ireland roughly equal to eastern County Clare of today. This strategic location guaranteed the tribe’s control of the estuary and waterway of the Shannon, Ireland’s main river, which provided access to the Midlands. When Brian was growing up early in the second half of the tenth century, this tribe began to emerge as a major player on the local political scene. Taking advantage of a power vacuum in the southern province of Munster, the Dál Cais formed alliances with various Munster parties, including the Norse city of Waterford. On the death of his brother Mathgamain in 976, Brian became the leader and prime mover of Dál Cais expansion. By the end of the tenth century, Brian was well on his way to establishing himself as the foremost king in Ireland. His extraordinary success was partly the result of natural ability and of divisions among his rivals that he was able to exploit.

At the turn of the eleventh century, Ireland was a political conglomerate of numerous petty kingdoms, known as tuatha, loosely bound together in five major provinces: Leinster in the east, Munster in the south, Connaught in the west, Ulster in the north, and Meath in north-central Ireland. Each of these provinces had its own over-king. In the thirty years after he became king of the Dál Cais, Brian progressively extended his influence, first over Munster, over the southern part of Ireland by 997, later over Meath, and eventually over Ulster by 1005. His relations with Leinster, however, were more problematic. To assert his authority over the southern part of Ireland, Brian needed to control Leinster, including the independent Norse city of Dublin. Following earlier forays into Leinster in 984 and 991, Brian defeated the Leinstermen at Glen Máma in late 999. Early in 1000, he plundered Dublin and compelled its ruler Sitric Mac-Aulaffe I Sitric Mac-Aulaffe I to submit. (Brian was well aware of the commercial and military advantages found in controlling Viking cities such as Dublin.) A few years later, Brian intervened politically in Leinster affairs by deposing Domhnall mac Donnchada as king of Leinster, replacing him with Máel Mórda mac Murchada Máel Mórda mac Murchada , who hailed from a north Leinster tribe.

Nevertheless, Leinster’s longstanding resentment against outsider control erupted again in 1013, possibly as a result of an insult suffered by Máel Mórda at the hands of Brian’s son Murchad Murchad . Máel Mórda not only withdrew his submission to Brian but also encouraged other subject tribes to do the same. In addition, Máel Mórda entered an alliance with the Norse residents of Dublin.

In the meantime, Brian was also gathering his forces. Along with his own army of Munstermen, Brian recruited forces from the southern Connaught kingdoms of the Uí Fiachrach Aidne and the Uí Maine. He advanced eastward through the border territory of Ossory (now southwestern Leinster) at the same time that Murchad proceeded northward through Leinster from the south. The two armies converged on the north side of Dublin, which Brian then besieged all through the autumn of 1013. After failing to take the city, Brian withdrew his forces by Christmas and returned home to Munster.

Realizing that Brian and his forces would return, the Norse of Dublin Dublin, Vikings and made preparations. Sitric Mac-Aulaffe visited his Norse allies in western Scotland and the Isle of Man. He won over Earl Sigurd Sigurd of the Orkneys and two prominent Viking leaders, Brodar Brodar and Ospak Ospak , who had a fleet on the Isle of Man. These allies agreed to be in Dublin with their ships by Palm Sunday of 1014. They may have deliberately chosen this date as a time when their Christian enemies would be preoccupied with the observance of Holy Week.

This time, Brian returned with an even larger army, although the advantage of superior numbers was wiped out when his ally, Máelsechlainn II of Meath, withdrew his forces on the eve of the battle. Arriving near Dublin, Brian ravaged the Norse suburbs of Fingal and Howth. The Norse and their Leinster allies marched out of the city to meet Brian. The battle was joined on the plains of Clontarf on the north side of Dublin, where the river Tolka runs into Dublin Bay. By this time an elderly man, Brian remained in his tent and left the conduct of the battle to Murchad.

The battle was fought all day, but by evening the Leinster and Norse armies gave way and fled toward the sea. The victory was marred by the slaughter of Brian in his tent by Brodar during his retreat inland from the battle. Other prominent casualties included Murchad and kings of the subject Munster tribes, as well as a grandson and nephew of Brian; casualties on the other side included Máel Mórda, Sigurd, and Brodar, as well as most of the prominent Leinster leaders. The victorious Munster army, led by Brian’s surviving son, Donnchad, returned home, but not without harassment from another Leinster tribe, the Osraige.


In no real sense could this battle be described as a decisive conflict between two national armies. Brian’s army consisted essentially of men from his own tribe and province; with the exception of Leinster, the rest of Ireland remained unengaged. Likewise, his enemies could not be characterized as Norse invaders as the majority of them were residents of Leinster. The role played by the Norsemen of Dublin was relatively minor, and the majority of these men were residents of Ireland, not invaders. As for the portrayal of Brian as the first real high-king of Ireland, it also falls short of being accurate. Brian certainly gave new definition and potential to this notion, but he never achieved a national monarchy and did not establish the institutions and administration normally associated with such an office.

How then does one explain the enormous significance that later time attached to the Battle of Clontarf? The memory of a protracted and bitterly fought battle, the death of a man who had already carved out for himself a special place in Irish history, and the propaganda produced a few decades later by Brian’s own people in The War of the Gaedhil with the Gaill all ensured a permanent place for the battle in Irish literary and pseudo-historical tradition.

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Byrne, Francis John. Irish Kings and High-Kings. Portland, Oreg.: Four Courts Press, 2001. Discusses the Irish tribes and the rivalries leading up to the Battle of Clontarf.
  • citation-type="booksimple"

    xlink:type="simple">Loyn, H. R. The Vikings in Britain. Rev. ed. Cambridge, Mass.: Blackwell, 1995. The author devotes three chapters to the early raids and subsequent large-scale invasions of Britain by Scandinavians. A highly regarded history of the Viking Age.
  • citation-type="booksimple"

    xlink:type="simple">Moody, T. W., and F. X. Martin, eds. The Course of Irish History. Rev. ed. Lanham, Md.: Roberts Rhinehart, 2001. A scholarly collection of articles that provides a useful introduction to Irish history. Contains illustrations, a chronological table, and an extensive bibliography.
  • citation-type="booksimple"

    xlink:type="simple">Ó Corráin, Donnchadh. Ireland Before the Normans. Vol. 2 in The Gill History of Ireland. Dublin: Gill and Macmillan, 1972. Provides insights into events surrounding the Battle of Clontarf.
  • citation-type="booksimple"

    xlink:type="simple">O Croinin, Daibhi. Early Medieval Ireland, 400-1200. New York: Longman, 1995. Discusses the beginnings of Irish history, its politics, and the Irish as a people.
  • citation-type="booksimple"

    xlink:type="simple">Otway-Ruthven, A. J. A History of Medieval Ireland. 2d ed. New York: Barnes and Noble Books, 1993. An overview of medieval Irish history and a good starting point for understanding events during the period before 1496.

Categories: History