The Norman-Anglo Conquest of Ireland began in 1169, when a mercenary invasion force from Norman-occupied Wales captured Wexford and Waterford. A year later they took Dublin, and then, over the next eighty or so years, they expanded in all directions, until they held about 75% of the island.

The mercenaries who invaded Ireland were French in origin: ethnic Normans who spoke Norman-French, not English. Their king was Henry II, the French speaking, ethnically Norman ruler of the vast Angevin empire, of which England was only a small part. They were descended from 10th Century Vikings who conquered western France and intermarried with the natives, and then, as part of the Norman military aristocracy which William the Conqueror had installed after the Battle of Hastings (1066), they had migrated to England and Wales, again intermarrying with the natives. They had no deep seated cultural roots either in England, or in Wales, or in France, or in Scandinavia.

Everywhere they went in Ireland, the Normans built castles and towns, as they had done in England.  They also intermarried with Gaelic nobility, establishing the celebrated Norman-Irish feudal families -- Fitzgerald, Burke, Costello and Butler -- who ruled much of Ireland under nominal suzerainty from England until late in the 16th Century. Within a few generations, the Normans were as much a part of the Irish landscape as were the Gaels.

The story of the Norman Conquest resembles a soap opera, pitting the wily, deceitful villain (Dermot MacMurrough) against the well meaning but hapless incompetent (Tiernan O'Rourke). MacMurrough and O'Rourke were mortal enemies. The antagonism between them dated to 1152, when O'Rourke had been humiliated by MacMurrough's abduction of O'Rourke's wife, Dervorgilla. But MacMurrough may not have been as culpable as it seemed. According to Irish folklore, it was Dervorgilla herself, then aged 44, who arranged the abduction, with MacMurrough, then aged 42, simply going along. Nevertheless, MacMurrough was hardly an innocent bystander, having eagerly accepted the invitation, and having staged a lifelike abduction, with horsemen, screaming victim, and all the trappings. O'Rourke recovered Dervorgilla the following year (1153), but he never got the revenge he wanted.

The subsequent hostilities between O'Rourke and MacMurrough were played out in the context of a larger battle between Rory O'Connor and Murtaugh MacLochlain for the high kingship of Ireland. O'Rourke was allied with O'Connor, the eventual winner, while MacMurrough supported, and more importantly was protected by, MacLochlain.

In 1166, finally, after a 10 year war, O'Connor defeated MacLochlain once and for all. O'Connor was magnanimous in victory. He reduced MacLochlain's petit-kingdom to a small area, and took hostages, but otherwise permitted him to live out his reign.

O'Rourke had no intention of extending similar generosity to MacMurrough. He got his revenge later that same year when MacLochlain (MacMurrough's long time protector) died, and O'Rourke, along with several cohorts, forced MacMurrough to flee Ireland.

But MacMurrough quickly regrouped. He sought help from Henry II, the aforementioned Norman ruler of the Angevin empire. To Henry, MacMurrough represented opportunity knocking. Henry had no enthusiasm for personally leading an expedition to Ireland -- after all, he had previously declined to do so, even after seeking and receiving the Bull Laudabiliter – but he had nothing to lose by encouraging MacMurrough. Thus Henry issued an open letter to his subjects, authorizing them to render military assistance to MacMurrough.

MacMurrough then contacted one of the great Norman leaders in Wales, the legendary "Strongbow" (a.k.a. Richard FitzGilbert de Clare, the earl of Strigoil). Initially, Strongbow was reluctant, but then MacMurrough offered Strongbow his eldest daughter, Aoife (Eva), in marriage, together with the right to succeed MacMurrough as king of Leinster. Finally, Strongbow agreed to lead an army into Ireland to restore MacMurrough to power.

With Strongbow on his side, MacMurrough then was also able to recruit a number of Norman and Flemish knights whose names now are common in Ireland: FitzHenry, Carew, FitzGerald, Barry, Prendergast, Fleming, Roche, Cheevers and Synott.

The impatient MacMurrough returned to Ireland with a handful of Normans in 1167, but O'Connor and O'Rourke soon forced him to submit. Always the master of deceit, MacMurrough even paid O'Rourke one hundred ounces of gold as reparation for abducting Dervorgilla. But MacMurrough was not discouraged. He knew that help was on the way.

The first Norman troop ships, about 600 in number, landed at Bannow Bay early in May 1169. MacMurrough and several hundred of his men promptly joined the Normans, and together they marched on Wexford. The Viking inhabitants directly confronted the invaders, expecting to find a rag-tag outfit of enthusiastic but poorly armed Irishmen. Instead they discovered a fully armed and disciplined professional army, ready for the kill. The Vikings were driven back into Wexford, and next day the town was forced to surrender.

Strongbow himself now set sail for Ireland. His advance guard, ten knights and seventy archers, was led by a magnificent young soldier-warrior from the FitzGerald family, Raymond Carew, commonly called 'le Gros' ('the Fat'). Le Gros landed north of Waterford and quickly built earthen ramparts which remain even today. Almost immediately, an opposition army -- several thousand Vikings and Gaelic-Irish from Waterford and the surrounding areas -- attacked le Gros and his contingent of eighty Norman and Fleming soldiers.

Incredibly, le Gros and his vastly outnumbered troops prevailed. Behind the ramparts, le Gros had concealed a herd of cattle, which he suddenly stampeded into the oncoming troops, trampling the front rank of the attackers. In all the confusion, le Gros and his force routed the remaining natives, seventy of whom were captured alive. As a message to Waterford, the prisoners' limbs were broken, their heads severed, and their bodies thrown over the cliffs.

Now Strongbow and his army of about two hundred knights and a thousand other troops joined le Gros, and two days later, they attacked Waterford. Twice the Normans were beaten off, but eventually le Gros breached the walls at a weak point, and captured Waterford.

Now MacMurrough's daughter, Aoife, came to Waterford, where she married Strongbow. A celebrated fresco in the British House of Commons depicts the wedding ceremony occurring at the close of the battle, against a background of burning buildings and dead Irishmen. The fresco is a classic example of artistic license, since Aoife did not arrive until several days after the battle. But the artist captured brilliantly the essential elements of the pact which MacMurrough had made with Strongbow two years earlier in Wales.

Strongbow and MacMurrough now set their sights on taking Dublin, which was a semi-independent Viking kingdom. With the wily MacMurrough leading the way, the Normans evaded an ambush laid by O'Connor and O'Rourke and arrived unscathed at the city walls. The Vikings were inclined to surrender, but while negotiations were still ongoing, le Gros and Milo de Cogan led their troops through a breach in the city walls and routed the city's ineffectual defenders. Asgall, the Viking-Irish King of Dublin, managed to escape with some of his Viking followers. As they sailed away, Asgall vowed to return and retake Dublin.

MacMurrough became deathly ill in April 1171, and while Strongbow was visiting him, Asgall, who had been forced to flee only nine months earlier, made good on his vow to return. He brought with him a fleet of ships carrying about a thousand Vikings, who mounted a fierce assault on Strongbow's Dublin. But even without Strongbow to lead them, the Normans prevailed. Asgall, who was taken prisoner, was tried, convicted and beheaded in the hall of what formerly had been his own palace in Dublin.

Upon MacMurrough's death, Strongbow returned to Dublin, only to be confronted by a revolt of the Leinster tribes, who were challenging Strongbow's right to succeed MacMurrough as King of Leinster. The revolt nominally was led by Murtaugh MacMurrough, Dermot MacMurrough's nephew and heir, who claimed that succession should be determined by Irish (Brehon) law, not his uncle's agreement with Strongbow. Significantly, Murtaugh had military support from the Ard Ri, Rory O'Connor, along with widespread support from the other Gaelic lords. The Gaelic plan was to lay siege to Dublin and to starve the Normans into surrender. But after two months, complacency set in, which gave the Normans their opportunity. Strongbow, le Gros, and Milo de Cogan, each with a contingent of 200 men, snuck out of the city, circled around behind O'Connor, and mounted a surprise attack. The daring initiative succeeded beyond all expectations, decimating O'Connor's army and terminating the siege. The victory established once and for all the Norman's military supremacy over both Viking and Gaelic Irish.

Nominally, Strongbow and his Norman troops were acting on behalf of Henry II, but Henry suspected -- with good reason -- that Strongbow planned to establish an independent kingdom in Ireland. But Henry wanted Ireland to become part of his Angevin empire, with the Normans serving as feudal underlords. To squelch any contrary plans Strongbow might have, Henry promptly traveled to Ireland, bringing with him 4,000 well armed troops as a show of force. The visit was an enormous success. Without a drop of blood being shed, Strongbow and the other Norman warriors capitulated and paid homage to Henry, as did virtually everyone else of importance, the Normans, the Irish, the Vikings, even the bishops. Ireland was now part of Henry's Angevin empire.

In 1175, the Treaty of Windsor was negotiated under which (1) Henry took for himself a large portion of Irish land already in Norman hands, including the area which later became known as "the Pale"; (2) The remaining land already in Norman hands was allocated among the Norman leaders; and (3) Henry agreed to accept Rory O'Connor as Ard Ri (high-king) of the unconquered areas, while O'Connor pledged himself to recognize Henry II as his overlord and to collect annual tribute for him from all parts of Ireland. But the treaty broke down almost immediately, for two reasons. First, O'Connor, the Ard Ri, found it impossible to collect tribute even in his home territory (Connacht), let alone elsewhere on the island. More important, Henry could not restrain his Norman barons from seizing more Irish land. Finally, Henry gave up on the treaty, and personally made several grants of large areas without consulting O'Connor or the other Gaelic kings.

In 1189, Henry appointed a Lord Protector of Ireland: His favorite son, John (then age 17), who served ten years and then became King of England (r.1199-1216).

Henry II died in 1189, and his vast Angevin empire (of which England was only a small part) quickly began to break apart. Henry II was succeeded by his son, Richard the Lionhearted (r. 1189-99), who was a magnificent warrior, but a terrible administrator. His glaring blunder was to concede that English monarchs were simply feudal under-lords to Philip II of France and his successors. Richard was succeeded by Henry's second son, the much maligned John I (r. 1199-1216), who had been Lord of Ireland since 1190.

Within five years of his coronation, John I found himself on the losing side of a war with King Philip II of France (1206). As a result of this military defeat, John lost most of the English possessions in France, including Normandy, Anjou and Brittany. Disastrous as these losses were, they would have been worse if they had been allowed to impact England's dominion over Norman-controlled Ireland. But John succeeded in utilizing military threats and intimidation to pressure the Norman-Irish lords into aligning themselves with England rather than France. At the time, England was ruled by a French speaking, ethnically Norman military aristocracy, although the ordinary citizen spoke English. Later when English kings reverted to the English tongue, the Norman-Irish lords -- descendants of the original, French speaking Norman invaders -- found themselves pledging loyalty to the English speaking Kings of England, rather than their French speaking rivals from France and Normandy.

The coronation of John -- truly a weak monarch -- insured that the remainder of the Norman Conquest of Ireland would be chaotic, with no master planning from the Crown. Chaotic or not, by the year 1250 -- only eighty years after their arrival -- the Normans controlled three quarters of the island.

The Normans, assisted by a partly Anglo work force, dramatically changed the face of inland Ireland, which previously had been entirely pastoral. Vastly outnumbered by the natives, the Normans congregated in small communities, which gradually evolved in towns, typically centered around a castle and/or church. Indeed, although the coastal towns of Dublin, Wexford, Waterford, Cork, and Limerick were established by the Vikings, the vast majority of inland and other towns and villages in Ireland were founded by the Normans. Munster, under Norman influence, became one of the most French of provinces outside of France itself.

After conquering an area, the Normans typically displaced the Gaelic nobility, or married into it, but the ordinary Irishman was left in peaceful possession of his land to herd cattle and till the soil, just as he had been doing under their native chieftains. But the Normans did insist that the natives adopt modern and more efficient agricultural practices.

Moreover, the Normans customarily built churches in their towns. Virtually all of the medieval cathedrals in Ireland -- St Patrick's in Dublin, St Mary's in Limerick, St Canice's in Kilkenny -- were the work of the Normans.

The original Normans imposed a feudal system substantially identical to that which their ancestors had brought from Normandy to England. They built Dublin Castle and installed a strong central government. They struck coinage for Ireland. They introduced English common law, including the jury system. They appointed Sheriffs. And although it served only the Norman-Anglo colony, an Irish parliament modeled on the English one was created in the late 13th century. Although parts of the feudal system of government were rejected by descendants of the original Normans, other parts survived.

By the mid-1200s, the Normans held about 75% of the island, but their expansion was on the verge of curtailment. At this point, Ireland was divided into three geographic, ethnic and cultural regions:
(1) The so-called "Pale" -- Dublin and a surrounding area about 30 miles long and 20 miles wide -- was the only area which was fully English. The Crown's writs and orders were followed, some English was spoken, English culture prevailed, and most of the inhabitants (Philip II later called them the "loyal English") thought of themselves not as Irishmen but as the Crown's colony in Ireland.
(2) Gaelic Ireland -- principally western Ulster and an area in the South along the western coast -- had never been conquered by the Normans, and naturally retained Gaelic customs and remained completely outside feudal society and English rule. The Gaelic lords (Philip II later called them the "wild Irish") thought of themselves as Irish, never as the Crown's colony.
(3) Norman-Irish Ireland, comprising about 70% of the island (everything except the Pale and Gaelic Ireland), consisted of the quasi-independent fiefs of the great Norman-Irish lords. In these areas, the Norman-Irish lords -- descendants of the original Norman invaders -- not only resisted the tight control of a feudal monarchy, but were beginning to adopt the Gaelic language and culture, and to assimilate into Gaelic society. These Norman-Irish lords (Philip II later called them the "English rebels") remained fundamentally loyal to the Crown, but had no interest in becoming part of a feudal monarchy that would strip them of power.