The O’Neill lineages project

Eneclann’s Research Director, Fiona Fitzsimons, was invited to give a talk by the O’Neill Clan Gathering on Friday 24 May 2013.  What follows is a brief synopsis of what was covered in the talk.


Thank you for asking me here today.

Let me tell you about a unique research project that I’m involved with – a fusion of the old and the new – blending the skills of research historians and genealogists with the expertise of medical geneticists.

What is the project?

We are tracing the main O’Neill lineages that emerged between the 13th and 17th Centuries, forward in time, and where possible, tracing descent along an unbroken male line to the present day.  This is because the family name, like the Y chromosome, is transmitted via the male line.

The geneticists will then use our work to take samples from each branch of the family, to define the ‘genetic signature’ for each lineage, and by comparing signals across lineages, they hope to shed light on the overall question of whether the O’Neill lordship had a common ancestor.

So, who might this common ancestor be?

Well within the project we refer to this as the ‘descent from Niall’ question.  The Niall in question is not Niall Naoighiallach – a mythical figure thought to have flourished c. 445-53? but the historical figure of Niall Glúndubh, king of the Cenél nEógain – the Northern Uí Néill, and High King of Ireland, who died in battle against the Vikings of Dublin in 919.

You might ask, how is it possible to document and trace a family across 1000 years, especially given Ireland’s reputation for destroying its historic records?

Image (right) reproduced under the terms of Wikipedia Commons


What is the methodology?

The Irish genealogies are among the oldest in Europe.  The earliest surviving texts are the 7th Century ‘genealogy poems’ that supposedly trace descent of the Leinster and Munster kings from Milesius – king of the Míl Espáine.  In the 11th Century the central hypothesis of the genealogy poems was reworked as the Lebor Gabála or ‘Book of Invasions’.  All the dominant dynasties – including the Uí Néill were said to descend from sons of Milesius.

In fact the idea that the earliest settlement of Ireland was from Spain, is not so far-fetched.  Genetic studies by Trinity college geneticists showed that Irish population are related to those living in north-western Spain.  So one of our earliest texts on the origins of the people of Ireland, has in fact been given some substance by medical science.

But we should not make the mistake of thinking that the traditional genealogy texts are ‘written in stone.’  More than most historical documents, Irish Genealogies have to be treated with caution.  As Katharine Simms has written – “Genealogies validated claims to land and kingship, so … [were] periodically revised, ignoring later generations of declining dynasties, finding a suitable origin for new arrivals on the political scene, or transferring lines from one ancestor to another to reflect new alliances.”[1]

The Ó Néill kings of Tír Eógain were descended from Niall Glúndubh.  The family were temporarily eclipsed but still remain visible in the Irish records.  And, from the Anglo-Norman invasion in 1170 until the Flight of the Earls in 1607, the Ó Néill of Tír Eógain were the main political power in the province of Ulster.  As such they were comparatively well documented in the historic records.  Its possible to use these documents as independent corroborative evidence to assess the accuracy of the genealogies, which after all were mainly concerned with where power lay within the extended O’Neill clan.

Building on the work of John O’Donovan, Paul Walsh, Kenneth Nicholls and Katharine Simms, we are in the process of identifying the main O’Neill lineages, and their territorial base.

The ceannfine, or Lord of the O’Neills of Tyrone.  Separate out as a distinct lineage from ca. 1455.

  • Einri 1455-83

Conn 1483-93

Conn Bacach 1519-59, 1st earl of Tyrone

Feardorcha d. 1558, son and designated heir of Conn Bacach

2.  Clandeboye –separate out as a distinct lineage by 1196-1230.

After 1553 the O’Neills of Clandeboye further separate into Clandeboye Upper and Lower.

3.  The O’Neill of the Fews, separate out as a distinct lineage after 1475.

We’re also interested in documenting the separate lineages of 3 brothers

Sliocht Airt of Omagh, descended from Art O’Neill (d. 1458)

O’Neill lineage of Arachta, descended from Felim ‘Balbh’ O’Neill (d. 1461)
Clann Chonnchadha, descended from Muricheartach d. 1471

And we’re curious as to whether there are any descendants of Turlough Luineach, a cadet branch that separated out from the main Tyrone branch ca. 1513 and established themselves in Strabane.

If this all seems straight-forward enough, we have encountered one problem – or should that be three – the Tudor Conquest; the Confederate Wars; and the Williamite Conquest.

Over approximately 130 years between ca. 1560s and 1690s, we had three conquests in rapid succession.  With each conquest the old ruling elite were dispossessed and legal records of land title were purposely destroyed, as a new ruling elite tried to entrench their position.

So how can we trace the descendants of those people who were dispossessed in the early modern period?

This is the final plank in our methodology.  We want to trace the descendants of these main O’Neill lineages, because they are documented in land records and pedigrees, and can be corroborated by using the records of central and local government.  But we are also interested in identifying the territorial base of each of these lineages.

We are interested in collecting DNA samples from O’Neill men:

  • where we can show that the earliest traceable ancestor of any O’Neill family came from this same place, and
  • where there is a tradition within the family of descent from this lineage.

Of course there will be ‘paternity incidents’ (infidelity) along the way, and this is part of the reason why we hope to widen the numbers of those from whom we collect DNA samples from.  But if anything, this also emphasises the importance of the dual disciplinary approach, in using genealogy and genetics, to try and establish proper control groups.

Thank you for listening.

For further information on the project contact:


[1] Oxford Companion to Irish History, 2nd edition, ed. S.J. Connolly.

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