My Ancestor, Tiernan O'Rourke, The Irish King

It’s St. Patrick’s Day, so it is a good time to explore the Irish king in my ancestry, Tiernan O’Rourke. Tiernan (or Tigernan Ua Ruairc) was king of Breifne, a region that no longer exists, from around 1124 until around 1172. Breifne was where the current counties Cavan and Leitrim are. At the height of its power (when Tiernan was king), it extended from County Meath to County Sligo.

They say that, in old Ireland, having a king in one’s ancestry is sort of like having an elected official in the family if you are from New Hampshire. The jurisdictions are so small that there are many such officials. That seems about right. Here are the kingdoms of Ireland around the year 900:

You can see Breifne there, in the middle of the North and the South.

Tiernan, Dervorgilla, and Dermot

Even though there were lots of kings and nobles back then, my Tiernan played a special role in history. You see, he had a neighboring king, one Dermot MacMurrough (Diarmait Mac Murchada). In 1152, MacMurrough stole my forebear Tiernan’s wife, whose name was Dervorgilla (Derbforgaill). Evidently, Dervorgilla planned this thievery. According to Irish historian Geoffrey Keating:

[T]he wife of Tighearnan Caoch O Ruairc (Dearbhforgaill was her name, and she was daughter to Murchadh Mac Floinn, king of Meath, and not wife of the king of Meath as Cambrensis says) sent messengers in secret to Diarmaid Mac Murchadha asking him to come to meet her and take her with him as his wife from Tighearnan and she told the messengers to make known to Diarmaid. that Tighearnan had gone on a pilgrimage to the cave of Patrick’s Purgatory, and that, therefore, he would have an opportunity of quietly carrying her with him to Leinster. There had been indeed an illicit attachment between them for many years previously.

As to Diarmaid, when this message reached him he went quickly to meet the lady, accompanied by a detachment of mounted men, and when they reached where she was, he ordered that she be placed on horseback behind a rider, and upon this the woman wept and screamed in pretence, as if Diarmaid were carrying her off by force; and bringing her with him in this manner, he returned to Leinster. As to Tighearnan, when he returned to Breithfne and heard that it was against her consent his wife was taken from him, he made a complaint of this outrage to Ruaidhri O Conchubhair [the High King of Ireland] and to his friends in general.

Upon this Ruaidhri made a muster of the men of Connaught, Breithfne, Oirghialla and Meath, and set out with a large host to waste Leinster to avenge this evil deed Diarmaid had done.

O’Rourke mounted an expedition the next year, 1153, to steal back Dervorgilla. This “exchange” sealed the bad blood between MacMurrough and O’Rourke for good.

Dermot Travels To France With A Proposal

As the years progressed, the political landscape in Ireland shifted until, finally, MacMurrough was forced from his lands in 1166 and fled to France, where he sought out King Henry II. MacMurrough was set on regaining his lands and was looking for sponsorship.

MacMurrough found Henry, finally, in distant Aquitaine, and made his case. He knew Henry had ling been interested in Ireland. MacMurrough would help him, so long as Henry helped him return to power. According to the Old French Song of Dermot And The Earl:

Hear, noble king Henry,
Whence I was born, of what country.
Of Ireland I was born a lord,
In Ireland acknowledged king;
But wrongfully my own people
Have cast me out of my kingdom.
To you I come to make plaint, good sire,
In the presence of the barons of your empire.
Your liege-man I shall become
Henceforth all the days of my life,
On condition that you be my helper
So that I do not lose at all
You I shall acknowledge as sire and lord,
In the presence of your barons and earls.

Henry said he was too busy with other matters to invade Ireland. However, he did encourage MacMurrough to pull together his own forces and forge alliances with other Irish kings — and gave him a letter urging all of Henry’s subjects to rally to MacMurrough’s aid. MacMurrough returned to Ireland in 1167 and set about his new task with gusto.

MacMurrough’s first try was a failure. He set up residence near Ferns, but O’Rourke attacked him and he surrendered — and was forced to pay one hundred ounces of gold in compensation for his wife-stealing fifteen years earlier.

But that did not stop MacMurrough. He bided his time and amassed resources and forces. Eventually, he was ready to restart his campaign to take Ireland on behalf of King Henry II. In 1169, Norman forces loyal to Henry joined MacMurrough and the capture of Ireland began in earnest.

Eventually, this resulted in the Norman conquest of all of Ireland. (Many more were involved, it was not just MacMurrough. Indeed, his role diminished over time.) O’Rourke bitterly fought against MacMurrough throughout, including laying siege to his forces after they had captured Dublin. But, finally, MacMurrough and his allies prevailed. The Normans occupied Ireland until 1541.


Tiernan O’Rourke lived until roughly 1172. As part of the distribution of power, O’Rourkes remained in power as Kings (later Lords) of Breifne until 1605.

Even though he was a cuckold, I hold an abiding pride in my illustrious ancestor Tiernan O’Rourke. His story is dramatic and shows how very human emotions (love, jealousy, rage) can drive historic events.

Learning about Tiernan O’Rourke made me curious to know more about my family lineage. In my studies, one thing I learned that my coat of arms is two black lions on a yellow background, an image I find very attractive.

I also learned that the family motto is “Serviendo Guberno.” I learned that this means “I lead by serving.” This has stuck with me and I have come to try to live my life by this motto (as have other O’Rourkes and Rourkes) — I try to serve others as the highest form of leadership.

I don’t always succeed, but I try.

As a reminder to myself, I have gone so far as to have my family crest and motto memorialized as a tattoo.

Published by

Brad Rourke

Executive editor of issue guides and program officer at the Kettering Foundation.

11 thoughts on “My Ancestor, Tiernan O'Rourke, The Irish King”

  1. Greetings from Kells, County Meath.I have liked and shared this article to Meath Today Facebook page.Check it out for daily updates,Noel Shine

  2. Hello Brad.
    Around 1650, a man named James ORourke (various spellings) arrived in Maryland.  His descendants became most of the ORRICKs in the US, and many other spellings, including Orick, Arick, Arrick, Rook, O’Rouke, etc, etc.

    Recently, my DNA testing is matching people by the name of Tiernan and similar spellings.  Very interesting. 

  3. Brad, if you’re interested in going further with this, I’d be glad to include you in the DNA study.  My name is Arrick.  It took about 2000 hrs of research to prove I was really an Orrick.  My particular branch had a tough go during the civil war and even lost the spelling of its name. 

    To find me, use the googler with “arrick/orrick genealogy” and that’s me.

  4. Been doing family research. I have 26,000 names in my family database. My grandmother was a Roark and I am a descendent of Tiernan O’Rourke and visited the former Roark (O’Rourke) Castle in Sligo …which is now Parke Castle. Also visited Dermot MacMurrough’s grave in Ferns.

    An interesting situation for the visiting of both of these places. My gg+grandmother was Dervorgilla O’Rourke. My husband’s gg+grandfather was Dermot MacMurrough. So, yes, my husband’s grandfather “kidnapped” my grandmother. Apparently the families (through us) have reunited and forgiven each other. :)

  5. Hello Brad, I don’t know whether you can help me , but here goes! Until my late grandfather’s funeral we always thought his surname was Kenny, it turns out that in fact his birth surname was O’Rourke and he was adopted. He married my late grandmother Ellen Costello who was born in Tipperary/Kilkenny. Her family lived in Thurles. I have been trying to research my family history but to no joy.
    Hope anyone out there can help make sense of my jigsaw puzzle! Best wishes Michelle Holmes (nee Kelly).

  6. Thanks so much for your note . . . I wish I could help! I really know so little about this stuff, to be honest. But perhaps a reader can weigh in with some assistance! ~Brad

  7. Hi Brad. I too am descended from Tiernan and did go to Leitrim in the 1980’s to see the Castle snd tour the area. Saw all the O’Routke graves at the Abbey too. Climbed the mountain “O’Rourkes Table” with a descendent of Mac Murrough’s. Funny that. The motto is By ruling I serve”

  8. Been trying to find my grandfathers family history. Managed to find him his parents and siblings from west Meath not as easy as I thought it would be but will keep trying. Really enjoyed reading your article thanks.

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