Diarmait Mac Murchada

So the inevitable invasion of Ireland by the Anglo-Norman forces of King Henry II of England was initiated by an invitation from Diarmait Mac Murchada (anglicized as Dermot MacMurrough), the one-time King of Leinster. The illustration of him here is from a copy of Gerald of Wales' Expugnatio Hibernica ("Conquest of Ireland").

Diarmait (c.1110 - May 1171) had an illustrious background. His father, Donnchadh, was King of Leinster. His great-grandmother was descended from Brian Boru. His father died while attacking the King of Dublin in 1115; succession passed to Diarmait's older brother, Enna. When the brother died in 1126, the 16-year-old Diarmait became king.

This was not welcomed by the then-High King of Ireland, Toirdelbach Ua Conchobair (Turlough O'Conor), who saw Diarmait as a potential rival. Turlough sent an ally, Tigernán Ua Ruairc (Tiernan O'Rourke), King of Meath, to harry Leinster and oust Diarmait. Tiernan started slaughtering Leinster livestock to starve the inhabitants. Diarmait was ousted, but Leinster clans brought him back in 1132, where he remained for almost 40 years.

Between 1140 and 1170, Diarmait built Abbeys at Fern and Baltinglass, Killeshin Church, and St. Saviour's Priory. He sponsored numerous convents. He also had two wives—not in succession but concurrently, as allowed in early Irish/Brehon law. (This was another reason why the Roman Church wanted stronger influence in Ireland.) His first wife was the mother of a son who later succeeded Diarmait. His second wife was the mother of a daughter, Aoife.

There was a rumor that Diarmait kidnapped Tiernan's wife, aided by Tiernan's brother who wanted Tiernan out of the way and his kingship of Meath up for grabs. Tiernan must have had issues getting along with others, since the High King actually used Diarmait's help much later to raid Tiernan's lands because Tiernan had become problematic.

In 1166, a different High King was defeated by Ruaidrí Ua Conchobair (Rory O'Conor), who deposed Diarmait by sending Tiernan (again!) to Leinster. Diarmait fled to Wales and sought support from King Henry. Henry did not wish to get directly involved, but gave permission for Diarmait to seek help from the nobility. One who agreed to help was the 2nd Earl of Pembroke, Richard de Clare, to whom Diarmait promised his daughter Aoife (Eva of Leinster) in marriage (and the kingship of Leinster after Diarmait's death).

So began the Norman invasion of Ireland. The military aid was so useful that Diarmait used it to expand his territory to Thomond. Initially it was a Cambro-Norman invasion because it was begun by Welsh lords, but it was soon followed by the Anglo-Norman invasion when Henry's own forces arrived to subdue the island and make sure the Norman lords knew to whom they owed allegiance.

One of the "beneficiaries" of the invasion was the Roman Church, allowing it to bring the Irish Church into conformity. One of the facets of Irish culture that the Church wanted to "fix" was the law that allowed Diarmait to have two wives. This Brehon Law is worth exploring further, and we will do just that next time.

Henry's Invasion of Ireland

The first mass arrival of Normans in Ireland was actually by invitation of Diarmait Mac Murchada, King of Leinster until he was deposed by the High King of Ireland, Ruaidrí Ua Conchobair. Diarmait got military aid from Richard de Clare, the 2nd Earl of Pembroke, with King Henry's permission. In exchange, Pembroke would receive Diarmait's eldest daughter's (Aoife) hand in marriage.

Offering allegiance to Henry for the support, Diarmait led Pembroke's Anglo-Norman forces around to some of the neighboring kingdoms, subduing them within weeks. That was not to be the end of it, however.

Pembroke continued to bring military forces, seizing Dublin and Waterford in 1170. With Diarmait's death in May 1171, Pembroke (by virtue of his marriage to Aoife) declared himself Lord of Leinster. This was too much for the Irish, who planned a counteroffensive, besieging Dublin and attacking the Norman-controlled Waterford and Wexford. The Normans were too strong and entrenched, however.

Five months after Diamait's death, Henry himself landed with a large army to assert control over the Irish and the Anglo-Normans, lest they tried to be too independent. He declared any of the Norman-controlled towns as crown lands and gave Pembroke Leinster as a fiefdom. Many Irish kings submitted, probably hoping to prevent further conquest, but Henry gave Meath to Hugh de Lacey, and William FitzAldhelm got Wexford.

Henry also arranged the Synod of Cashel to reform the Irish Church. Henry had the blessing of the Roman Catholic Church. The Church (especially the Archbishops of Canterbury) wanted to make sure the Irish Church was conforming properly: they had not fully adopted the Gregorian Reforms. Pope Adrian IV in a 1155 papal bull, Laudabiliter, seemed to give Henry encouragement to conquer Ireland in order to bring them to Roman rule:

That Ireland, and indeed all islands on which Christ, the sun of justice, has shed His rays, and which have received the teaching of the Christian faith, belong to the jurisdiction of blessed St. Peter and the holy Roman church is a fact beyond doubt, and one which your nobility recognises.

(Then again, Adrian IV was the only English pope, so he may have had a particular tendency to favor what he considered English causes. Curiously, Laudabiliter is frequently cited and quoted since the 13th century, but no original exists.)

This was the start of eight centuries of English/British unwelcome involvement in Ireland. It was bound to happen anyway, but curious that it was initiated by invitation. Let's go back a little further and see what Diarmait Mac Murchada, King of Leinster, was all about.