List of kings of Leinster in the context of "Uí Dúnlainge"

The Anglo-Norman invasion of Ireland took place during the late 12th century, when Anglo-Normans and Cambro-Normans gradually conquered and acquired large swathes of land in Ireland over which the monarchs of England then claimed sovereignty. The Anglo-Normans claimed the invasion was sanctioned by the papal bull Laudabiliter. Gaelic Ireland then consisted of several kingdoms, with a High King claiming lordship over most of the other kings. The Anglo-Norman invasion was a watershed in Ireland's history, marking the beginning of almost 800 years of British presence in Ireland.

In May 1169, Anglo-Norman mercenaries landed in Ireland at the request of Diarmait mac Murchada (Dermot MacMurragh), the deposed King of Leinster, who sought their help in regaining his kingship. They achieved this within weeks and raided neighbouring kingdoms. This military intervention was sanctioned by King Henry II of England. In return, Diarmait had sworn loyalty to Henry and promised land to the Normans.

Diarmait Mac Murchada (Modern Irish: Diarmaid Mac Murchadha; anglicised as Dermot MacMurrough or Dermot MacMurphy; c. 1110 – c. 1 May 1171), was King of Leinster in Ireland from 1127 to 1171. In 1167, he was deposed by the High King of Ireland, Ruaidrí Ua Conchobair. To recover his kingdom, Mac Murchada solicited help from King Henry II of England. His issue unresolved, he gained the military support of the Richard de Clare, 2nd Earl of Pembroke (otherwise known as "Strongbow"), thus initiating the Anglo-Norman invasion of Ireland.

In exchange for his aid, Mac Murchada promised Strongbow the hand in marriage of his daughter Aoife and the right to succeed to the Kingship of Leinster. Henry II then mounted a larger second invasion in 1171 to ensure his control over Strongbow, resulting in the Norman Lordship of Ireland. Mac Murchada was later known as Diarmait na nGall (Irish for "Diarmait of the Foreigners"). He was seen in Irish history as the king that invited the first-ever wave of Anglo-Norman settlers, who were planted by the Norman conquest. The invasion had a great deal of impact on Irish Christianity, increasing the de facto ability of the Holy See to regulate Christianity in Ireland.

The Battle of Clontarf (Irish: Cath Chluain Tarbh) took place on 23 April 1014 at Clontarf, near Dublin, on the east coast of Ireland. It pitted an army led by Brian Boru, High King of Ireland, against a Norse-Irish alliance comprising the forces of Sigtrygg Silkbeard, King of Dublin; Máel Mórda mac Murchada, King of Leinster; and a Viking army from abroad led by Sigurd of Orkney and Brodir of Mann. It lasted from sunrise to sunset, and ended in a rout of the Viking and Leinster armies.

It is estimated that between 7,000 and 10,000 men were killed in the battle, including most of the leaders. Although Brian's forces were victorious, Brian himself was killed, as were his son Murchad and his grandson Toirdelbach. Leinster king Máel Mórda and Viking leaders Sigurd and Brodir were also slain. After the battle, the power of the Vikings and the Kingdom of Dublin was largely broken.

The royal sites of Ireland were the seats of the Gaelic kings of Ireland. Medieval sources describe them as the ceremonial capitals of various Irish kingdoms, where kingly inaugurations, assemblies and athletic games were held. Archaeological investigations show that many royal sites were culturally significant for thousands of years before recorded history, and they often include ancient monuments such as Neolithic burial mounds, standing stones, cairns and enclosures.

Each Irish kingdom is thought to have had its own royal site, but six sites are considered to be the most important. These are Tara (Irish: Teamhair), seat of the Kings of Meath and the High King, along with the provincial capitals: Navan Fort (Eamhain Macha) for Ulster; Rathcroghan (Cruachan) for Connacht; Knockaulin (Dún Ailinne) for Leinster; and Cashel (Caiseal) for Munster. Uisneach represented the union of the provinces and may have served as a meeting place for the kings. These major sites, excluding Navan Fort (in Northern Ireland), have been listed as a potential UNESCO World Heritage Site.