McMahon clans

[1] According to historian C. Thomas Cairney, the MacMahons were one of the chiefly families of the Dal gCais or Dalcassians who were a tribe of the Erainn who were the second wave of Celts to settle in Ireland between about 500 and 100 BC.

[2] The Thomond MacMahons were part of the great tribal grouping, the Dál gCais, and claimed descent from Mahon O'Brien, son of Muirchertach Ua Briain, High King of Ireland.

[6] In August 1585, the Irish leaders of Thomond were forced to sign an Indenture with Sir John Perrott, the English Lord Deputy of Ireland.

Sir Turlough Roe MacMahon, Baronet of East Corcabaskin, received the honour of becoming High Sheriff of County Clare in 1609.

According to an Inquisition held at Ennis in 1630 (reported in Frost's "History ... of Clare"), Turlough's title was inherited by his eldest son, Sir Teige MacMahon.

Ainsworth's edited Inchiquin Manuscripts, MS No 1845, at p. 625, contains a note made following the death of Mary Rua O'Brien in 1686 which refers to "her nephew Sir Terlagh McMahon".

The McMahon Clan is directly descended from legendary General and High King of Ireland Brian Boru "Conquorer of the Danes at Clontarf".

The motto was originally a battle cry and roughly translates to "Here's a fist to the dark-blooded","This hand is raised against tyrants","Beware of retaliatory blows" or "Guard against counterblows".

They trace descent from The Three Collas to their patronymic namesake, Niall Mac Mathghamhna, who descended from Mathgamna, Lord of the ancient kingdom of Fernmaige, located in the modern Baroney of Farney.

It was a MacMahon, Colonel Hugh Oge's loose lips, that were responsible for letting slip the plot to seize Dublin Castle.

Coat of Arms for the MacMahons of Thomond
Coat of Arms of the MacMahons of Oriel
Early peoples in Ireland and the seven provinces as defined in the 11th-century Lebor na Cert (Book of Rights)