Mac Mathghamhna's Ladrannaibh


MacMahon's Bandits

Caldragh, County Fermanagh

Caldragh...County Fermanagh


The first time the surname Mac Mathghamhna shows up in the literature of ancient Irish history is this: 

AU1181.1 (Annals of Ulster)

'Aedh Mac Murchadha, royal chief of Muinnter-Birn and the Airthir and the Cantred, was killed by Mac Mathgamna in treachery, at a meeting.'

This citation is unclear about to whom it may refer because it does not provide a first name though it most likely refers to Niall.  Fifteen years later Niall begins to make his mark on history on a more regular basis when, in 1196, Niall Mac Mathghamhna (later anglicized as MacMahon or Mac Mathúna in modern Irish) is noted in the literature.  Interestingly, and not surprisingly, Niall is referred to as a bandit or rebel.  The Irish word used is Ladrannaibh.

Also not surprisingly there is some question about who Niall was or from whom he was descended.  Niall Mac Mathghamhna is descended from Mathgamna several generations earlier, but whether he is cousin (see Clan Nadsluaig) or brother to the murdered Muircheartach (Morrough) O'Carroll, the last O'Carroll King of Airghialla, is apparently in doubt (see below).  Our dna project does show that Mac Mahon and O'Carroll are related.

From Bandits to Kings....

Prior to 1196 the Mac Mathghamhna surname is not prominent in the literature, though there is one reference as noted above.  The surname is generally agreed to derive from the ancestor Mathgamna, Lord of Fearnmaig who died at Clones in 1022 and from whom descended the O'Carrolls and the Mac Mahons.  Livingstone suggests that the Mac Mahon descendency from the O'Carroll line was invented, but the literature provides two different genealogies for Niall, one descending from the O'Carroll line and another as a cousin to the O'Carrolls.  We suspect the latter is the correct one.

Just prior to Niall emerging, the O'Carroll Clan had taken a mighty beating by the Normans.  Historians have claimed that the MacMahons may have played a role in this as a means to advance their own standing.  That may be true, but it is not evident in the literature or the lineage.  Meanwhile, historians do not seem to have focused much on the emergence of Niall.  Whether he was brother or cousin to the O'Carrolls, it would appear that he did not join the O'Carroll migration eastward.  Perhaps he stayed behind for a reason.  Perhaps he was determined to stay and fight.  For whatever reason, either he or his father adopted the name of his ancestor, Mathgamna, thus distinguishing their line  from the O'Carrolls and establishing Clan MacMahon.  This was during the period of time when surnames were just beginning to be used and often the adoption of a surname had political purposes or certainly a purpose related to making a clear distinction of one clan from another.

When Niall appears in the literature, it is with a certain flair.  The following represent his recorded exploits:

Louth was plundered and burned, together with its castle, by Niall Mac Mathghamhna and John de Courcy.

The following extract provides further insight into this event: "Immediately after the English invasion, when de Courcy entered Ulster, he was joined by a chieftain named MacMahon who ingratiated himself so much with him that he was entrusted with the command of two forts, which, on the first change of fortune, MacMahon utterly destroyed; and, when questioned on his breach of faith, answered that he was not engaged to keep stone walls; that he scorned to confine himself within such cold and dreary enclosures while the native woods were open for his reception and security."  (source: Livingstone, p. 44, references Lewis, p. 341)

To interpret for you, de Courcy (and de Lacy below) are Normans.  Niall apparently joined de Courcy in plundering Louth but then when entrusted with its castles he destroyed those, proving to be rather independent and not a great ally for de Courcy.

What is odd about this account and a cause for further thought, is that de Courcy had nearly been killed himself by the O'Carrolls, had engaged with them in battle on numerous occasions, and had no doubt been involved in the blinding and hanging of Muircheartach O'Carroll.  And here we have Muircheartach's close relation joining de Courcy as an ally in the plundering of Louth, albeit some seven years after Muircheartach's death.  Niall then manages to gain control of the English castles and destroys them.  From that point on he makes a practice of destroying English castles.  So, who was this Niall?  And just what was he up to?

The monastery of Peter and Paul [i.e. Clones] was plundered and burned by Bratach Buile Ó Maothagáin and Mac Mathghamhna's bandits. [In the same year Teach Damhnata (Tydavnet), Ceall Muragáin (Kilmore?) and Clones were burned by Hugh de Lacy.]


Éighneachán Ó Domhnaill, king of Cinéal Conaill, and many others were killed by Niall Mac Mathghamhna, the Fir Manach and Tuath Rátha, as they were plundering the country as far as Fochraobh.  (One source has Niall Mac Mathghamhna leading the Fir Manach and Airghialla into this battle.)

A castle [was built] at Caoluisce Locha Éirne [i.e. Belleek] by Henry Beck (?) for the king of England, and he himself was killed there by Ó Néill and Mac Mathghamhna.


A castle [was built] at Clones by a force of the king of England's men, and they made a foray to Abha Tíre Crithmuium, and defeat and slaughter [were inflicted] on that force by Ó Néill and MacMathghamhna.

From the later Rawlinson manuscript, included in the same volume, comes the following;

The battle of Carn tSiadhail was fought by Domhnall Mac Lochlainn, and in it Domnall Tamhnaighe Ó Néill, Mac Mathghamhna, nobles of Cinéal Moáin, and a number of others were killed.

This Niall Mac Mathghamhna seems to have waged his own private war against England for some 40 plus years.  History has recorded him as Ladrannaibh, or bandit.   (see Clan Nadsluaig)  Without this 'bandit', there certainly would have been little chance for the MacMahon line to become Kings of Oriel.  The citations above are known to be Niall from 1196 through 1207.  Those after this date refer to Mac Mathghamhna and so we have no way of knowing if this is Niall or a son or nephew who may have taken over by this time.

Why was he referred to as a bandit?  We can only provide conjecture, but the Irish have a habit of providing people with nicknames.  His was Niall Uaibhreach, which can be interpreted as proud or arrogant.  The word Ladrannaibh can be interpreted as other than 'bandit'.  What we can surmise here is that we have a very daring man who was willing to raid neighbors, church lands, implement taxes, and hire mercenaries in order to take control of Airghialla.

A segment of Niall's genealogy is in doubt.  There are two sources, both of which having him descending from Mathgamna, Lord of Fernmaige (d 1022) but each describing him as descended from different sons of Mathgamna.  These are as follows:

The Book of Lecan has the lineage as: 'Niall son of Donchadh son of CuCaisil son of Donnell son of Mathgamna....'  This is from the Book of Lecan, folio 79 recto, but subsequently modified by Donald Schlegel to eliminate what appears to be an error.  Nonetheless, the lineage is as cited.  Donchadh is an O'Carroll king, in fact a rather prominent one.

The other source, a mid-fourteenth century manuscript National Library of Ireland G 2, folio 26r (25) lower margin, reads: 'Niall mc Aeda mc Fhaelan mc Matgamna....' and on back to Colla de Crioch.  This source would have Fhaelan as a brother or nephew of the name Donnell cited above.

A third citation (TCD MSS H.4.31 states on p. 52)  has Niall as the son of Aeda (Hugh) and brother to Mathghamna, as follows: Eachaidh (1275) [s. Mathgamhain] s. Aodh and includes the following quote:

'and another son of this Aodh was Niall the Arrogant, and it was because of the
oppressiveness of his taxation and his lordship that the chiefs fled from Modharna of Oirghialla into Trian Conghail, and from that migration the land in which many of them dwell today is named Modhorna of Iveagh.'

Here are the citations in Irish:

This tract appears in Trinity -(Trinity was written in 1668)

as mc. ele don  Aodh sin Niall Uaibhreach, 7 ase (le) truime a chiosa 7 a
thiagernus ro   theichseatt na taosigh as Mugarna Oirghiall a tTriuin Conghail, 7
as don  tsiubhal sin sloinnter an fearann attreabhaid moran diobh aniugh, .i.
Mugharna    Iath Eathach

      translation -

another son of this Aodh was Niall the Arrogant, and it was because of
the oppressiveness of his taxation and his lordship that the chiefs fled from 
Modharna of Oirghialla into Trian Conghail, and from that migration the land 
in which many of them dwell today is named Modhorna of Iveagh

  This tract appears in Lecan -
(Lecan is the original version and was written around 1400)

Mc. eili d'Aed mc. Faelain, .i. Niall Uaibrech.  As tre truma a tigernais do   
techsead taisig Mugdorn Oirgialla a Trian Congail conidono geineamain  
sloindter in ferand aitrebait aniu .i. Mudorna.

As you can see, there is the suggestion that Niall was a lord of Oirghialla and that he had or imposed the authority to tax the other chiefs who resided there.  Or he was a lord of a smaller area within Oriel, perhaps Lord of Mugdorn as suggested above.  Keep in mind that he comes from the branch of the Lords of Fernmaige in western Monaghan so it would not be surprising for him to hold the title of Lord, whatever that implies.  Fearmaige translates to 'the Alder Plain' and is today a lovely valley north and west of Clones.  The word also translates to the modern word: Farney.  The Lords of Fearmaige relocated from ancient Farney to the modern day barony of Farney, the area around Carrickmacross.  When this migration occurred is not known, but since the surname Mac Mathghamhna is said to have arisen from Loch Leck, in modern Farney it is likely that the migration took place just before Niall's emergence and very likely due to the pressures caused by the Norman incursion into Oriel.

In any case, all sources agree that Niall descends from Mathgamna, the original Lord of Fernmaige who died in 1022, with the question of whether he was born into the lineage of Mathgamna's son Donnell or Fhaelen.  Another possibility is that there is a missing name, another of Mathgamna's sons who would have been Fhaelen's father.  We have installed both possible genealogies for Niall on the Clan Nadsluaig genealogy page.  We've now done an exhaustive study of each of the references to Niall's genealogy and concluded that the G2 manuscript at Trinity College represents the oldest of the recordings and is most likely to be the accurate portrayal.  It does appear that a generation if missing between Mathghamna and Fhaelen.

An Analysis of the Pedigree of Niall Mac Mathghamhna

What the reader must understand and which is hard to convey is the motivation behind modifying the pedigrees of people such as Niall.  We have a situation in which the MacMahon branch of the family were likely installed by the O'Carrolls as subchieftains within the Airghialla federation, governing a local territory.  With the elimination of the O'Carroll Kings by the Normans there was a leadership vacuum.  It appears that both the MacMahons and the O'Hanlons attempted to fill this vacuum.  With the Norman conquest of Louth and the separation of Fermanagh under the Maguires, Oriel is essentially limited to a fraction of its former size.  But both competing families seem to have held visions for restoration of the former kingdom, perhaps not realizing that the Norman conquest was to change their way of life permanently.

The ancient Irish custom of derbfine required that a legitimate Irish King descend from a family of Kings.  So it was likely with this in mind that after the MacMahons established themselves that either they were responsible or the Irish scribes acting on their own made a deliberate attempt to modify their genealogy to make them descend directly from the O'Carrolls.  This would legitimize their claim.  At the same time, it is possible that their genealogy had already been recorded accurately but with no recollection of who Fhaelen's father was, in the G2 manuscript.  Thus we end up with two versions (and other variations) of Niall's pedigree.

The above quote from the TCD MSS H.4.31 manuscript brings another issue into focus  and that is whether or not Niall acted in the capacity of king of Oriel while conducting his various battles.  We originally noted on Hugh McGough's web page several references to Niall ( ) as Niall the Haughty, Niall the Arrogant, etc.  These are both English interpretations of the Irish word 'Uaibhreach', ie: Niall Uaibhreach.  Niall is called Uaibhreach in the Fermanagh Genealogies.  The citation on Hugh's website implies that Niall was taxing the people of Oriel.  This implies that Niall had taxing authority, or assumed a taxing authority.  This intrigued me and led us to attempt to determine if in fact Niall was the first MacMahon King of Oriel, whether recognized by others or simply by taking the position by force. 

We inquired about this to the Irish scholar Dr. Katharine Simms and she had the following to say by email: "There is a problem of terminology between pre-Norman Airgialla, meaning the loosely federated kingdoms of Ui Cremthainn, Ui Nadsluaig, Airthir, etc. (Fermanagh, Clogher Valley Tyrone, Monaghan and Armagh with some of Louth) and the post-Norman kingdom of Oirghialla from mid-13th century onwards, where the meaning is confined to the modern Co. Monaghan.  Two Ó hEignigh kings of Fermanagh are called King of Airgialla in the Annals of Ulster just before and after 1200, but there is a case for seeing Niall MacMahon as wielding de facto kingship for some of this time, as the annals describe Niall as leading both the Fir Manach and the Oirghialla in battle to defeat ODonnell in 1207 or 1208 [Misc. Ir. Ann., p. 86, Ann. Loch Cé i, p. 236 (1207 A.D.); Ann. Ulster ii, p. 248 (1208 A.D.)].  About the time Eochaidh MacMahon became the first formally recorded MacMahon king of Oirghialla, Donn Carrach Maguire became the first formally recorded Maguire king of Fermanagh, signalling the loss of Co. Louth to the Normans, and the political separation of Fermanagh and Monaghan in the second half of the 13th century. On the other hand, Eachmharcach O Hanlon, king of the Armagh area, who killed Eochaidh MacMahon in battle in 1273, subsequently used the title 'King of Oirghialla' later that same year in its old sense of 'overlord of the Airgialla federation'. See my article 'The O'Hanlons, the O'Neills and the Anglo-Normans in 13th century Armagh' in the journal Seanchas Ardmhacha vol. 9 (1978), 70-94."

As the reader may sense from this passage above, it is most likely that Niall was essentially acting in the capacity of king of a much smaller Airghialla, much as the O'Carrolls had previously done.  Certainly his actions led to the rise of the MacMahon kings and gave a prominence to this new branch of Gaelic chieftains who subsequently arose to that position with Eochaid becoming the first 'formally recorded' MacMahon king of Oirghialla around 1250 AD.  On the other hand this citation might well be inaccurate. The citation suggests that Niall's unfair tax drove ('...because of the oppressiveness of his taxation and his lordship that the chiefs fled...') caused a migration out of Oriel.  Other documentation however suggests that this same migration took place some 40 years before Niall came on the scene.  What we can be sure of is that Niall acted to fill a vacuum created by the deaths of the O'Carrolls and that he was successful in establishing the MacMahons as a force to contend with in the new, much diminished Oriel. 

Whether or not all of the above Annal references refer to Niall we cannot be sure.  It seems unlikely that he could be responsible for actions beginning in 1181 and extending to 1239. That would make him some 78 years old at the time of his death.  While this is possible, it is certainly a long and interesting life for one so 'active'.  It is possible, since some of the references only use the surname, that his father and son or nephew were included in these actions.  The term MacMathghamhna then would be in reference to the position, essentially 'The MacMahon', a term that came to be applied to the person holding the highest leadership position.

We will shed more light on this fellow as we learn more.  Many thanks to Hugh McGough for finding this reference and many thanks to ancestor Niall, whether he was 'haughty' or 'arrogant', he was most certainly one hell of a rebel and he seems to have lived a long life for one so daring.  These were indeed dangerous times....


~ Brian Mac Domhnaill

~ Donald M Schlegel

~ Shane Anderson

~ John MacLaughlin

 ~ Seamus Mac Mathghamhna

July 2003

This tale of the Mac Mahon bandits comes from Mac Carthaigh's Book, contained within a collection titled Miscellaneous Irish Annals, edited by Séamus Ó hInnse and published in 1947 by the Dublin Institute for Advanced Studies, an excellent source for changes in the overlordhip of Fearnmhagh (Farney in the vicinity of Clones) in the early Middle Ages.


Next Chapter: Rise of the MacMahons

A Listing of all Genealogies for MacMahon

Niall's Pedigree

Origin of the Name Mathgahamhna

Meaning of the Name Mathgahamhna

O'Carroll Kings

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