MacMahon (No.1) family genealogy
Lords of Corca Baisgin, County Clare
Arms: Ar. three lions pass. reguard. in pale gu. armed and langued az. Crest: A dexter arm in armour embowed ppr. garnished or. holding in the hand a sword both ppr. pommel and hilt gold. Motto: Sic nos sic sacra tuemur.
TURLOGH MÓR, the 178th Monarch of Ireland, who died A.D. 1086, and is No. 107 on the "O'Brien" (of Thomond) pedigree, had two sons: 1. Mathghabhuin[1]; 2. Dermod: this Mathghabhuin was the ancestor of MacMathghamhna anglicised MacMahon.
108. Mathghabhuin ("magh:" Irish, a plain; "gabhuin," a calf): son of Turlogh Mór; a quo MacMathghamhna (of Munster).
109. Morogh: his son.
110. Dermod MacMahon: his son; first of this family who assumed this sirname.
111. Morogh na Mongnach: his son.
112. Donogh: his son.
113. Dermod: his son.
114. Rory Buidhe [boy]: his son.
115. Donogh na Glaice: his son.
116. Teige Roe: his son; had a brother named Donogh.
117. Teige (2): his son.
118. Turlogh (or Terence): his son.
119. Teige (3): his son. This Teige had two brothers—1. Brian; and 2. Donogh (or Donatus), who (there is reason to believe) was the ancestor of "MacMahon" of France.[2]
120. Morogh: son of Teige.
121. Teige (4): his son.
122. Turlogh Roe: his son.
123. Sir Teige: his son.
124. Sir Turlogh MacMahon, of Corca Baisgin (now the barony of "Moyarta," in the county Clare: his son.
Notes
[1] Mathghabhuin: This name means "the bear of the plain," or a "wild calf;" for a bear is strictly a kind of wild calf. From this word is derived the surnames Mahon, MacMahon, Mahony, and O'Mahony; but it may be here observed that the "Mahon" and "MacMahon" families of Munster are distinct from the "Mahon" and "MacMahon," of Ulster.
[2] MacMahon of France: Patrick MacMahon of Torrodile, in the county Limerick, having espoused the cause of King James the Second, settled in France after the Treaty of Limerick, A.D. 1691. His son, John MacMahon of Autun, in France, was created "Count de Equilly;" who, in order that his children and his posterity might have sufficient proof of "the proud fact that they were of Irish descent, applied on the 28th September 1749, to the Irish Government (accompanying his application with necessary facts, etc., for the Officers of Ulster King of Arms) to have his genealogy, together with the records, etc., of his family duly authenticated, collected, and recorded, with all necessary verification. All this was accordingly done, the various requisite signatures affixed thereto, and countersigned by the then Lord Lieutenant of Ireland. In these records, preserved in the Office of Arms, Dublin Castle, Count de Equilly is described as of "the noble family, paternally, of 'MacMahon,' of Clondeas (in the county Clare), and maternally, of the noble family of 'O'Sullivan Beara.'" This John MacMahon (Count de Equilly) was the grandfather of Marshal MacMahon of France, Duke of Magenta, President of the French Republic; born A.D. 1808, and living in 1887.