The Fall of the MacMahons

and the

End of Oriel

Painted on a stone wall in Carrickmacross

"The English conquest of Ireland began with the Anglo-Norman invasion of 1169.  It was still far from complete four hundred years later, when under the Tudor kings and queens it had developed a new sense of urgency.  Even in the second half of the sixteenth century many of the Irish chieftains did not seem to realise that there was a conquest in progress at all.  Among these were the MacMahons of Monaghan."  Peadar Livingstone The Monaghan Story

'Here is the fist of the dark-blooded'

This is an enhanced version of the MacMahon Shield.  The use of coats of arms were a Norman invention and came into use as our people were on the brink of decline.  Our appears to have been designed with the Normans in mind.


As we learned in the story of the three baronies of Oriel the MacMahons were preoccupied with their own troubles.  They seemed to view the dominant O'Neill clan as more of a threat than the English and were known to ally themselves with the English with the hope that the annual tribute paid to the O'Neills could be eliminated.  They were also preoccupied with arguing among themselves.  What they and other chieftains of the day missed was the fact that the English invasion was to eliminate their whole way of life and replace it with another, one to which their traditions and culture would fail to adapt.  The 'English conquest would ultimately abolish their rights, their privileges, their laws, their customs, and their culture.' (Livingstone)

Hugh O'Neill became the O'Neill chieftain around 1593.  He played a major role in organizing the smaller Irish chieftains and preparing for war with the English.  The O'Neills controlled present day County Tyrone and the MacMahons presented a major problem for O'Neill in that the MacMahons were directly between O'Neill countrie and the path of the English.  Hugh O'Neill attempted to build alliances with the MacMahons.

Ross Bui MacMahon of the Monaghan branch of the Clan succeeded his father to the title 'MacMahon' in 1579.  Hugh O'Neill gave his daughter in marriage to Ross Bui to solidify the alliance.  Even after this Ross Bui apparently continued to seek alliance with the English in an attempt to rid himself of O'Neill influence.

In 1585, Sir John Perrot, the natural son of King Henry VIII, visited the area and met with the Irish chieftains.  The Irish themselves requested of him that Ulster be divided into shires and land apportioned to each of the MacMahon chiefs.  A commission was established to accomplish this and County Monaghan came into being.  The County was subdivided into the five baronies that exist today: Farney, Cremorne, Dartrey, Monaghan, and Truagh.

Afterward, Ross Bui made further attempts to build an alliance with the English and rid himself of O'Neill.  Hugh O'Neill gave another daughter in marriage to Brian Mac Hugh Og of the Dartrey MacMahons.  At stake was claim to the title 'Mac Mahon' after Ross.  Under Irish law Brian Mac Hugh Og had claim to the title.  In an attempt to establish his brother Red Hugh as the successor, Ross made further alliances with the English.  This led to further troubles and by June of 1589, Ross Bui was dead as a result.

In 1591 the English again reapportioned the lands in Monaghan and again the MacMahons retained control of the majority of the land, but the English began slowly to give land to outsiders, bringing in strangers from the Pale as well as English Lords.  This apportionment led to increased resentment and by 1593 the MacMahons and their cousins the Maguires took to the field in revolt.

Still the MacMahon infighting continued.  Hugh Maguire, the sons of Ever Mac Con Uladh MacMahon and Brian Mac Hugh Og MacMahon entered Monaghan, then ravaged Farney, plundered Talbot's lands in Louth then returning to attack the English garrison in Monaghan town.  Shortly afterwards though, Patrick Mac Art Moyle, Patrick Dubh and other MacMahons joined an English force attacking the home of Brian Mac Hugh Og, plundering Dartrey and burning Brian's house on the shores of Rooskey Lake and the crannogs on Rooskey and Drumca lake.

The Nine Years War began in earnest in 1594 and was the last major struggle to preserve Gaelic Ireland.  The MacMahons continued to fight among themselves while Hugh O'Neill had not yet officially joined the war and continued to build alliances in preparation.  In 1595, O'Neill officially endorsed the inauguration  of Brian Mac Hugh Og as 'MacMahon' and supported an invasion of Farney that restored Ever Mac Con Uladh to his ancestral home.  By these acts, O'Neill gained the support of two of the important MacMahon leaders.  Shortly afterward, Hugh O'Neill joined the war against the English.

For a time it seemed that O'Neill did well against the English.  When things did not go well, the Irish would craft a truce with the English, then regroup or harvest their crops, addressing their immediate needs, only to attack the English again when the timing suited them.  By 1597 things looked well for O'Neill.  But the arguing among the MacMahons continued and O'Neill was not able to keep them together as allies.  In 1598, the year of O'Neill's greatest victories, Patrick Mac Art Moyle claimed title of MacMahon in opposition to Brian Mac Hugh Og. 

In 1600 Baron Mountjoy led the English efforts against O'Neill.  His strategy was to surround O'Neill on all sides and by May 1601 Mountjoy could claim that Farney, the Fews in Armagh, Clancarrol, the O'Hanlons, as well as many of the MacMahons and O'Reillys were 'reduced'.  The MacMahons who surrendered to Mountjoy included Ever Mac Con Uladh, Patrick Mac Art Moyle, Art Mac Rory Mac Brian, and Brian, the brother of Red Hugh.  Meanwhile, Brian Mac Hugh Og was still at large and continued to fight.

In September 1601 the Irish, including Hugh O'Neill and Brian Mac Hugh Og suffered a major defeat at Kinsale.  O'Neill and Brian Mac Hugh Og held out for almost two more years, attempting to negotiate a favorable surrender.  But Mountjoy had invaded and retaken Monaghan and would not come to terms.  In March, 1603 Brian Mac Hugh Og, the last of the MacMahons to do so, surrendered.  Later that year O'Neill surrendered, bringing an end to the Nine Years War.  England had now completed their conquest of Ulster.

the 'proudest and most barbarous sect among the Irish'

By this time, the war had had its effects and Monaghan had become a bleak place.  The English attorney general, John Davies described the area as 'the wastest and wildest part of all the north'.  Davies further described the MacMahons at the 'proudest and most barbarous sect among the Irish'.  And, as told by Peadar Livingstone, what was lost at Kinsale 'was a whole way of life'.

The effect of the loss was not immediate.  The MacMahons retained control of much of their lands.  But they were not able to adapt to the ways of English law and culture.  Taxes were imposed and there was no way to pay them.  The Irish failed to understand why they should pay taxes on lands that had always been theirs. 

Sir Edward Blayney, an Englishman, was installed as governor and granted substantial land holdings in 1607.  In 1624, Blayney wrote from Castleblayney, 'To speak truly, the MacMahons are neither willing nor able to pay anything and that is the case of the whole country, for all is waste and now I am labouring to get Scottes...'

Slowly, the Irish nobles sold off their lands in order to meet their tax obligations.  By 1640 local ownership of lands went from seventy eight to forty six percent.

'If the Rising of 1641 was inevitable it was also inevitable that it would end eventually in disaster for the participants.' Livingstone

The Rising of 1641 was to result in the greatest defeat the Irish had yet experienced.  The Irish rose against the English but when the wars were over, the remaining Gaelic nobles were mostly dead.   Prior to the Rising, the MacMahons are listed in the tax records as owning some 78 townlands.  After the wars, the MacMahons are no longer listed as landowners in County Monaghan. 

To add additional perspective for you, I was amazed to see only 112 Mac Mahons listed in the Pender's Census in Monaghan in 1659.  I mentioned this to Don Schlegel and here is his response: 'I noticed your surprise that there were only 112 McMahons in Monaghan in the 1659 "census."  That would be surprising to me also, but this was only 20+ years after the 1641 rising, when they threw themselves almost unarmed against the Scottish settlers in neighboring Fermanagh and against the British settlers in Louth, who of course had good fire-arms.  The Monaghan dead were in heaps by the time their siege of Drogheda was broken.  So the low number really isn't surprising in that light.' (source: Schlegel, email of 1-9-04)

And so it came to be that the once great Kingdom of Oriel that had lasted for some 1300 years came to an end.  Its rulers were dead.  Starvation, poverty, and pestilence followed in its wake.  Subsequent years brought greater difficulties and with those Clan MacMahon scattered, many seeking new lives elsewhere.  Eventually, the story too was lost to all but a few scholars.

Jim McMahon

October 2002

Headstone from the Donagh graveyard, a site associated with the McMahons.  Castle Leslie in nearby Glaslough is said to have been built on the site of a McMahon castle.  This gravestone is not necessarily that of a family member. 



Next Chapter: The MacMahon Lineage

Irish History in Maps:

English Settlement in Ireland circa 1600


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