The McMahon Story:

    The Clan MacMahon is descended from The Three Collas, brothers who were nephews to the High King of Ireland.  As the story is told, these three were daring and ruthless and attempted to take all of Ireland in 322 AD.  They ended up ruling a portion of the island consisting of Counties Monaghan, Armagh, and parts of Fermanagh, Louth, and Tyrone.  Their descendents were to rule this part of Ireland for some 1300 years, this Kingdom of Airghialla, later known as Oriel.  The MacMahon branch descended from a fellow known as Mathghamhain, who was slain in 1022.  The first Mac Mahon to hold the title 'King of Airgialla', according to the Annals of the Four Masters, was Eochaidh Mac Mahon who became King in 1250 and was killed in 1273.  The MacMahons continued to rule Oriel for some 400 years.  These were tumultuous times and change was in the wind.  Ireland consisted of perhaps 300 small kingdoms.  Powerful families on all sides were constantly seeking to expand their lands.  Gaelic rule was coming to an end.  The Normans were gaining in power....but I am getting ahead of myself.  There is a story to be told in these pages.  Let us begin at the beginning and end at the end.  Join us as we brush away the overgrowth and peer into the past.... 


 Welcome McMahons, for this is your story:


   Chapter 1: Airghialla


   Chapter 2: The Story of the Three Collas


   Chapter 3: Airghialla ~ from the Collas to the MacMahons


   Chapter 4: Mac Mathghamhna: From Bandits to Kings 


   Chapter 5: The Rise of the Mac Mahons


   Chapter 6: The Three Baronies: Dartry, Farney, and Lucht Tighe


   Chapter 7: Lough Leck and the Coronation Stone of the Mac Mahon Kings


   Chapter 8: The Fall of the Mac Mahons and the End of Oriel


   Chapter 9: The Mac Mahon Lineage - Collas to Mac Mahon                                           


   Chapter 10: Remnants on the Landscape:

        Faerie Forts


       Lost Castles


    Chapter 11: Ancient Traces in County Down


   Chapter 12: County Monaghan and the Kingdom of Oriel


   Epilogue: Closing Remarks


I developed the site. Everything I know is published herein. I can't help you find your relatives. I have given you a glimpse of your very dramatic ancestry. Be proud of it. We are warriors one and all: jim at jamespmcmahon dot com

   Additional Resources:

We have provided only the simplest overview of the historical account of the MacMahons.  If you want even more detail, we have provided a list of documents about the McMahons which are available from a variety of sources at this link:  Additional Reading and Reference Materials  

   Author's notes:

    You will notice numerous spellings for what appear to be the same name or reference.  These are not typographical errors.  They represent either a different translation of the same name or the increasing anglicization of names from traditional Gaelic to English over time. 




The Meaning of the Name: McMahon or Mac Mathghamhna

Search for your own roots - do research or look up family trees

An Index of Clare & Oriel McMahon sites - which clan do you belong to?

Variations of Mahon, Mac Mahon, and other names

A Tour of McMahon Sites in Modern Monaghan - 'going home'

Places to stay - two great places

Credits, Acknowledgements, Copyrights, and Thanks

Site Authors and Contributors   

The Mahons of Tullamore - a connection found

The Mac Mahon Irish Annals ~ a summary of all references in the Irish Annals

McMahon Surname DNA Project - join this study and learn your particular roots

Famous McMahons Today - links to websites of our clan



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Contact me if you have ideas, comments, or would like to contribute to various sections. 

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James Patrick McMahon

Seamus Padraig Mac Mathghamhna

January 2004


copyright, 2004

 See the Credits, Acknowledgements, Copyrights, and Thanks page to learn where we obtained various materials.


Visit frequently to learn the story




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