This section is taken with appreciation from the book A History of Ireland by Peter and Fiona Somerset Fry.
After the death of Brian Boroime (Boru) in 1014 at the battle of Clontarf no other high king had the strength
to unify Ireland which fell into violence and disorder. Alliances shifted, hostages were given and seized, fierce rivalries broke out, churches and homesteads were burned, and men from the different kingdoms fought and raided one another. In 1151, in the midst
of all the turmoil, an event of apparent insignificance took ace.Diarmait Mac Murchada, the king of Leinster, carried off the wife of Tigernan Ua Ruairk, the king of Breifne (where Cavan and Leitrim are now). The next year Derbforgaill was
back under her husband’s roof; a trivial escapade seemed to be over; but as a result of it, everything was to change.
Tigernan could not forgive the insult he had suffered. He conceived an implacable hatred of the younger Diarmait and
years later, in 1166, he saw his chance for revenge. Diarmait had allied himself with MuirchertachMac Lochlainn, who had earned the revulsion of the Irish kings and chieftains by treacherously blinding the king of Ulidia, although
he had already submitted to Muirchertach and had his submission guaranteed by other princes. In the furor that followed, Toirrdelbach’s son Ruadri Ua Conchobair won the high kingship, Diarmait Mac Murchada lost
his patron, Tigernan attached him, the Ostmen of Dublin and various Leinster chieftains, who normally supported him, joined in the attach and Diarmait was, in effect, driven out of his kingdom. On 1st August 1166
he took the step which has blackened his name forever. Taking his marriageable daughterAife with him, he sailed to the port of Bristol, which was already familiar to him, to seek the aid, in the form of an army, of Henry II of England.
Frenchman) was not only king of England; he ruled more of France, including Normandy, than the French king himself, and it was in early 1167 when Diarmait came up with him in Aquitaine. Henry greeted him with his usual bluff amiability, made him
gifts and, in return for Diarmait’s allegiance, gave him permission to recruit help from among his barons. Henry could not lose by the arrangement. He had not promised to help Diarmait personally, but if Diarmait found enough
support among Henry’s vassals to win his kingdom of Leinster back, Henry, as his overlord, would have a foothold in Ireland. He gave Diarmait an open letter, addressed to “all his liegemen, English, Normans, Welsh and Scots’, which
read: “know you that we have taken Diarmait, prince of the men of Leinster, into the bosom of our grace and goodwill. Wherefore, too, whosoever within the bounds of our dominions shall be willing to lend him aid, as being our vassal and liegeman,
in the recovery of his own, let him know that he has our favour and permission to that end.”
Diarmait went back to Bristol and looked for help. He had Henry’s letter read out in public several times, and made liberal offers of land
and bounty. For a while, there was no response. Then Richard Fitzgilbert de Clare, the Norman earl of Pembroke, generally known as Strongbow, came forward. He was out of favour at court, restless, discontented, and eager for an adventure like
the Irish one. He obtained Henry’s written consent to it, Diarmait offered him the hand of his daughter Aife in marriage and the deal was done. Next, Diarmait went into South Wales to recruit the help of Strongbow’s kinsmen,
Diarmait did not wait for his Norman supporters. Taking a handful of mercenaries with him, he sailed for Ireland in the autumn of 1167 and lay low in a monastery at his capital, Ferns, for the winter when he was not being attacked
by Tigernan or the high king until 1169 when a further 40 knights and 400 archer mercenaries came to his support. Diarmait recovered his lands and made peace with the high king. Once he was re-established as the king of Leinster Diarmait had
aspired to the high kingship himself. He was still owed help by his daughter’s betrothed, Strongbow, and wrote to the Welsh-Norman earl in 1170 reminding him of his two-year-old promise. Strongbow sent Raymond Le Gros, one of the Geraldines,
ahead of him with about ninety men who ruthlessly defeated about 2,000 Ostmen and Irish from Munster after landing at Baginbun in Wexford. At the last moment, when Strongbow, was about to embark, messengers came from Henry forbidding
the expedition. Too late -
Strongbow had made his plans, collected his men and set sail for Ireland. Two hundred knights and a thousand archers took ship with him at Milford Haven and landed near Waterford on 23rd August, an
event described prophetically in the Irish Annals of Ulster as ‘the beginning of the woes of Ireland”. Two days later, aided by Raymond, he took Waterford by assault. Diarmait brought Aifa to him and their marriage was solemnized
in Waterford cathedral.
Diarmait led Strongbow and his army to Dublin where they stormed the city, defeating the high king who left the most important town in Ireland to its fate. Then in May 1171 Diarmait died, aged 61, at
Ferns. WhenDiarmait betrothed his daughter Aifa to Strongbow, he may, or may not, have promised Strongbow that he could inherit the kingdom of Leinster after his death. Under the feudal law of the Normans, such an inheritance
would have been perfectly possible, and Strongbow assumed the kingship. But a king could not name his successor under Irish law. When a king died, his successor had to be elected from amongst eligible members of the royal family, ‘a stranger
in sovereignty’ was unacceptable and the succession could never pass through a woman. Diarmait had no eligible sons left, both having been killed. But he did have a nephew,Muirchertach, and the people of Leinster rallied to him.
the high king, Ruaidri and kings from all over Ireland were by now seriously alarmed by the presence of the Normans and formed an army of perhaps 30,000 to bring against them. The Irish were brave but indolent soldiers who wore
no armour and fought as a horde, in disarray. They surrounded the city of Dublin and prepared to starve the Norman forces of no more than 200 knights, 400 other mounted men and 1,500 archers and foot soldiers into submission. But the Normans had the most advanced
military techniques in Europe, were highly trained, and equipped with the latest weapons and amour. After two months had passed some 600 of the Normans slipped out and of the city into three divisions, spread out and attached the flank of the Irish army. The
Irish were completely taken by surprise; the high king and some hundreds of his followers were caught bathing in the river. The great besieging army was totally routed.
Henry II watched these events with some anxiety. Strongbow was too successful,
suppose he was to conquer Ireland, become high king and abandon his allegiance, leaving a strong Norman led kingdom off the Welsh coast treathing his empire. Henry assembled an impressive force, with 500 knights and about 3,000 archers, portable
wooden towers for sieges and castle building, and vast quantities of provisions, and then summoned Strongbow to him. Strongbow obeyed the summons and renewed his oath of fealty. Henry took the best of Strongbow’s conquest
- Dublin, the eastern coastal strip and all the coastal towns and fortresses – and confirmed Strongbow in possession of Leinster. He then set sail for Ireland with his army to claim the homage of all the kings and chieftains of Ireland.
Before leaving Ireland Henry appointed Hugh de Lacy, another Norman baron from Wales, who had come over in his train, to be his justiciary, or chief officer, in Ireland, to counterbalance the power of Strongbow, whom he still did not trust, waited
for a favourable wind and then, on 17th April 1172, took ship at Wexford and sailed away. De Lacy was granted the kingdom of Meath.
One hundred years earlier, England had been conquered by the Normans, aggressive cousins of those Vikings
who had made such inroads into Ireland. The Normans had been Northmen, that is, Scandinavians, mainly from Norway, whose hunger for new lands and opportunities had led them, in the ninth and tenth centuries, to northern France where they had wrested a
duchy from the native aristocracy and then adopted the French language, manners and customs.