Diarmait Mac Murchada

Diarmait Mac Murchada, anglicized as Dermot MacMurrough (died 1 January 1171) is considered the most notorious traitor in Irish history. Ousted as king of Leinster, he invited King Henry II of England to assist him in regaining the throne. The subsequent invasion led to Henry becoming Lord of Ireland himself, and marked the beginning of eight centuries of English dominance.

Contents

1 Early Life and Family 2 King of Leinster 3 Exile, Return and Death 4 Death and Descendants 5 Sources 6 Source for Genealogy

Early Life and Family

Mac Murchada was born around 1100, a son of Donnchad, King of Leinster and Dublin; he was a descendant of Brian Boru. His father was killed in battle in 1115.

Mac Murchada had many wives and concubines, the first of whom, Mór Ua Tuathaill, was mother of Aoife of Leinster and Conchobar Mac Murchada. By Sadb of Uí Faeláin, he had a daughter named Orlaith who married Domnall Mór, King of Munster. He had two illegitimate sons, Domnall Cáemánach (died 1175) and Énna Cennselach (blinded 1169).

King of Leinster

After the death of his older brother, Mac Murchada unexpectedly became King of Leinster. This was opposed by the then High King of Ireland, Tairrdelbach mac Ruaidri Ua Conchobair who feared rightly so that Mac Murchada would become a rival. King Tairrdelbach sent one of his allied Kings, the belligerent Tigernán Ua Ruairc to conquer Leinster and oust the young Mac Murchada. Ua Ruairc went on a brutal campaign slaughtering the livestock of Leinster and thereby trying to starve the province's residents. Mac Murchada was ousted from his throne, but was able to regain it with the help of Leinster clans in 1133. Afterwards followed two decades of an uneasy peace between Ua Conchobair and Diarmait. In 1152 he even assisted the High King raid the land of Tigernán Ua Ruairc who had by then become a renegade. Mac Murchada also abducted Ua Ruairc's wife Derbforgaill along with all her furniture and goods, with the aid of Derbforgaill's brother, a future pretender to the kingship of Meath.

After the death of the famous High King Brian Boru in 1014, Ireland was at almost constant civil war for two centuries. After the fall of the O'Brien family (Brian Boru's descendants) from the Irish throne, the various families which ruled Ireland's four provinces were constantly fighting with one another for control of all of Ireland. At that time Ireland was like a federal kingdom, with four provinces (Ulster, Leinster, Munster and Connaught) each ruled by kings who were all supposed to be loyal to the High King of Ireland.

Exile, Return and Death

In 1166, Ireland's new High King and Mac Murchada's only ally Muirchertach Ua Lochlainn had fallen, and a large coalition led by Tigernán Ua Ruairc (now Mac Murchada's arch enemy) marched on Leinster. Ua Ruairc and his allies took Leinster with ease, and Mac Murchada and his wife barely escaped with their lives. Mac Murchada escaped to England where he formed an alliance with King Henry II who helped him organize a mercenary army of Norman and Welsh soldiers to invade Ireland. Among them were Richard de Clare, 2nd Earl of Pembroke, alias Strongbow, who married Mac Murchada's daughter, Aoife of Leinster , in 1170.

In his absence Ruaidri mac Tairrdelbach Ua Conchobair (son of Mac Murchada's former enemy, High King Tairrdelbach) had become the new High King of Ireland. Mac Murchada planned not only to retake Leinster, but to oust the Uí Conchobair clan and become the High King of Ireland himself. He quickly retook Dublin, Ossary and the former Viking settlement of Waterford, and within a short time had all of Leinster in his control again.

He then marched on Tara (then Ireland's capital city) to oust Ruaidri. Mac Murchada gambled that Ruaidri would not hurt the Leinster hostages which he had (including Mac Murchada's eldest son, Conchobar Mac Murchada). However Ua Ruairc forced his hand and they were all killed.

Diarmait's army lost the battle and the Norman and Welsh mercenaries whom he had hired soon aided an invasion by England's Henry II in 1169. Mac Murchada lost his will to fight after his son's death, retreated to Ferns and died a few months later.

Although in modern Irish history Diarmait Mac Murchada is often seen as a traitor, his intention was not to aid an English invasion of Ireland, but rather to use Henry's assistance to become the High King of Ireland himself. He had no way of knowing Henry II's ambitions on Ireland.

Gerald of Wales, an Anglo-Welsh historian who visited Ireland and whose uncles and cousins were prominent soldiers in the army of Strongbow, said of Mac Murchada:

"Now Dermot was a man tall of stature and stout of frame; a soldier whose heart was in the fray, and held valiant among his own nation. From often shouting his battle-cry his voice had become hoarse. A man who liked better to be feared by all than loved by any. One who would oppress his greater vassals, while he raised to high station men of lowly birth. A tyrant to his own subjects, he was hated by strangers; his hand was against every man, and every man's hand against him."

Death and Descendants

After the invasion the Normans conquered Ireland by playing one Irish family off against another. Ua Conchobair was soon ousted, first as High King and eventually as King of Connaught. Attempting to regain his provincial kingdom, he turned to the English as Mac Murchada had before him. By 1171, England directly controlled a small territory in Ireland surrounding the city of Dublin known as "the Pale", while the rest of Ireland was divided between Norman and Welsh barons sent by the English, and the various Irish Clans (like the Uí Conchobair who retained Connaught and the Uí Néill who retained Ulster).

Subsequently most of the ruling Norman families began to intermarry with the Irish. Eventually they allied with Irish clans against England, adopted the Irish language and as the English put it "became more Irish than the Irish themselves" prompting a second English invasion centuries later.

See also Kings of Leinster

Sources

• "Annals of the Four Masters", ed. J. O'Donovan; 1990 edition.
• "Expungntio Hibernica", by Geraldus Cambrensis. Martin & Moody, editors.
• "Irish Kings and High Kings", Francis J. Byrne, 1973.
• "The Norman Invasion of Ireland", by Richard Roache, 1998.
• "War, Politics and the Irish of Leinster 1156-1606", Emmett O'Byrne, 2004.
• Gerald of Wales

Source for Genealogy

• Uí Cheinnselaig Kings of Laigin, "Irish Kings and High Kings" by Francis J. Byrne, page 290, Dublin, 1973.
• The MacMurrough-Kavanagh kings of Leinster, "War, Politics and the Irish of Lenister", Emmett O'Byrne, Dublin, 2004, Outline Genealogys I, Ia, Ib,, pages 247-249.