Normans Invade Ireland

Norman troops invaded Ireland in a series of small military expeditions—backed by Welsh and Flemish foot soldiers—and established a foothold in southeastern Ireland that provided the basis for England’s lengthy domination of Ireland and continuing involvement in Irish affairs.

Summary of Event

There was no well-conceived design by England’s King Henry II Henry II (king of England) to obtain control of Ireland. Henry, whose domains stretched from Scotland to the Pyrenees Mountains, was also duke of Normandy, count of Anjou, and ruler of Aquitaine through marriage to its duchess, Eleanor of Aquitaine. As such, Henry was lukewarm to the idea of taking on additional responsibilities. At a royal council held at Winchester in 1155, the idea of invading Ireland had been discussed but quickly put aside. It had been the English bishops, led by the archbishop of Canterbury, who had been the most enthusiastic in their support of such an invasion. [kw]Normans Invade Ireland (1169-1172)
[kw]Ireland, Normans Invade (1169-1172)
Ireland;Norman invasion of
Ireland;1169-1172: Normans Invade Ireland[2030]
Expansion and land acquisition;1169-1172: Normans Invade Ireland[2030]
Wars, uprisings, and civil unrest;1169-1172: Normans Invade Ireland[2030]
Henry II (1133-1189)
Adrian IV
Dermot MacMurrough
Eva MacMurrough
O’Connor, Rory
O’Rourke, Tiernan
O’Rourke, Dervorgilla
Richard de Clare
O’Toole, Laurence

The two kingdoms were utterly different from each other. England was a centralized, medieval monarchy, with a well-developed system of bureaucracy and an efficient administration whose workings ultimately stemmed from the king himself. In the hands of an energetic, detail-oriented monarch such as Henry, it could be a highly effective instrument. The English Church followed the Roman model and acknowledged the pope’s final authority. Ireland, however, maintained the centuries-old Celtic structure of its church. Government was decentralized, and territory was parceled into units controlled by tribal or clan groupings known as tuath. Tribal chieftains and clan leaders owed allegiance to different kings. Ultimately, all of the various kings theoretically pledged allegiance to an Irish high-king. The high-king, however, was considered a war leader or a “first among equals,” rather than a governmental or administrative head; there was no set rule determining who would be high-king. Heredity was only one factor to consider, out of many. Order and authority were generally maintained by force of arms, and each separate kingdom often enjoyed abundant autonomy. At any given time, there might be as many as 150 Irish kingdoms. The Irish Church also operated on an independent basis, differing from the Roman Church in many of its ideas and practices. During the tenth and eleventh centuries, Danish Vikings set up independent colonies that developed into urban centers—notably Dublin, Limerick, Waterford, and Wexford—further complicating Ireland’s fragmented political picture.

Pope Adrian IV.

(Library of Congress)

In 1152, Irish Church leaders had angered Theobald, the influential archbishop of Canterbury, by ignoring his claims to authority over them. In response, the archbishop pressured Henry into dispatching his emissary, John of Salisbury John of Salisbury , on a mission to Pope Adrian IV Adrian IV (pope) . Born Nicholas Breakspear, Pope Adrian was the first and only Englishman elevated to the papacy. In December of 1155, Adrian issued the since-refuted papal bull Laudabiliter (“donation of Ireland”), which authorized Henry to take control of Ireland and to restore the Irish Church to Roman practices. At the time, the gesture was ineffectual; Henry did not follow up on it.

Ireland’s internal politics, however, transformed the situation. Dermot MacMurrough, MacMurrough, Dermot king of Leinster, had maintained a long-standing feud with Tiernan O’Rourke, O’Rourke, Tiernan king of Breifne. Animosity between the two kings reached such a level of intensity that MacMurrough once abducted O’Rourke’s wife Dervorgilla O’Rourke, Dervorgilla and held her (not entirely against her will) for one year. O’Rourke never forgot this humiliation; when his powerful ally Rory O’Connor, O’Connor, Rory king of Connacht, became high-king of Ireland in 1166, MacMurrough was dispossessed of his kingdom and forced into exile.

In an attempt to regain his crown, MacMurrough sought out Henry in Aquitaine and implored his assistance in its recovery. Although he expressed sympathy, Henry refused to commit himself. Nevertheless, he authorized his subjects to help in restoring MacMurrough if they so desired. MacMurrough chose to concentrate his efforts at recruitment in the border country of South Wales. There, many tough young Norman warriors had been tempering their battle skills in clashes with Welsh tribesmen.

MacMurrough found the Normans quite willing to embark on an adventure in Ireland—for a price. In return for the promise of lands, money, or both, bands of Norman knights, Flemish foot soldiers, and Welsh bowmen agreed to sail across the Irish Sea on MacMurrough’s behalf. The most prominent of these mercenaries was Richard FitzGilbert de Clare Clare, Richard de , earl of Strigoil and Pembroke, who was popularly known as Strongbow. What this powerful noble asked, and received, was the hand of MacMurrough’ MacMurrough, Eva daughter Eva in marriage and the right of succession to the kingdom of Leinster. In 1167, MacMurrough led a small force of foreigners in his first attempt to reclaim his kingdom, and it proved to be an unqualified failure. In May, 1169, however, a more formidable contingent—thirty knights, sixty men-at-arms, and three hundred archers—under the command of half brothers Robert Fitzstephen Fitzstephen, Robert and Maurice Fitzgerald Fitzgerald, Maurice landed in County Wexford. Other landings soon followed, with Strongbow himself disembarking at Passage in County Waterford in August, 1170.

The lightly clad Irish, relying on wild, headlong charges and antiquated weaponry, proved no match for the less numerous but effective and well-disciplined Norman forces, nor could the urban Danes stand up to the Norman invaders. After a spectacular Norman success at Baginbun and the taking of Wexford and Waterford cities, Strongbow married Eva MacMurrough and marched on Dublin, which also fell into his grasp. On Dermot MacMurrough’s death in May, 1171, Strongbow laid claim to his domains but had to defend his claims against various rivals. Murtough MacMurrough, Dermot’s nephew, tried to wrest control of the kingdom of Leinster; Asculf, the exiled Danish ruler of Dublin, returned with Viking warriors from as far off as Norway. Cavalry charges scattered Asculf’s forces, and he was beheaded after a brief trial. O’Connor and O’Rourke then besieged Dublin, but they were beaten back after two months by a Norman surprise attack on the high-king’s camp.

King Henry, who became alarmed at the possibility that Strongbow might establish himself as an independent ruler, took a belated interest in the invasion and landed at Waterford in October, 1171. In the negotiations that followed, Laurence O’Toole, O’Toole, Laurence archbishop of Dublin, played a key role. O’Toole was largely responsible for persuading a synod of Irish bishops meeting at Cashel to submit to Henry’s rule and also negotiated Strongbow’s submission to the English king. Henry entered Dublin in triumph and received the submission of one Irish king after another. Although he allowed Strongbow to retain his position as ruler (not king) of Leinster, Henry appointed Hugh de Lacy, a trusted Norman, to serve as justiciar of Ireland and gave him authority over the former kingdom of Meath in order to balance Strongbow’s power.

Henry’s ultimate victory in Ireland occurred when he successfully negotiated the Treaty of Windsor Windsor, Treaty of (1175) in October, 1175. Under the terms of the treaty, High-King Rory O’Connor acknowledged Henry as his suzerain. O’Connor proved to be Ireland’s last effective high-king and was increasingly unable to assert his influence over the remaining lands of his realm. He died while on a religious pilgrimage to Cong in 1198. Strongbow died at Dublin in 1176, leaving no male heir; he was buried in Christchurch Cathedral.


The dominant position of the English government in Ireland had been established on an enduring foundation after the Norman invasion of Ireland and King Henry’s Treaty of Windsor. The invasion and treaty not only destroyed the tradition of the high-king in Ireland but also had the effect of asserting English influence over Irish affairs even today.

Further Reading

  • Cambrensis, Giraldus. Expugnation Hibernica: The Conquest of Ireland. Edited and translated by A. B. Scott and F. X. Martin. Dublin: Royal Irish Academy, 1978. A primary source account of the period whose author, a Norman-Welsh cleric, expresses a distinct anti-Irish bias.
  • De Paor, Liam. The Peoples of Ireland: From Prehistory to Modern Times. Notre Dame, Ind.: University of Notre Dame Press, 1986. An overview that covers the breadth of invasions, migrations, and influences entering Ireland from prehistory to the twentieth century.
  • Duffy, Seán. Ireland in the Middle Ages. New York: St. Martin’s Press, 1997. Irish historian’s effort to present Irish history of the period and not English colonial history.
  • Flanagan, Marie Therese. Irish Society, Anglo-Norman Settlers, Angevin Kingship: Interactions in Ireland in the Late Twelfth Century. New York: Oxford University Press, 1989. Scholarly reevaluation of primary source material that is accessible to laypersons. Stresses the role of the English Church.
  • Lydon, James F. The Lordship of Ireland in the Middle Ages. Rev. ed. Dublin: Four Courts Press, 2003. Important study of the medieval fusion of cultures, albeit one that ultimately rendered the Irish as secondary.
  • Moody, T. W., and F. X. Martin. The Course of Irish History. Cork, Ireland: Mercier Press, 1984. One of the most complete scholarly accounts of the sequence of events culminating in the establishment of Norman political control.