O'Brien (No. 9.)
Of Ballyetragh, County Waterford.
From Irish Pedigrees; or the Origin and Stem of the Irish Nation, by John O'Hart
TURLOGH MAOL, second son of Murtagh, who is No. 115 on the "O'Brien" (Kings of Thomond) pedigree, was the ancestor of "O'Brien" of Bun‑Cumeragh, in the county Waterford. The O'Briens of Ballyetragh are a branch of that family. Several other branches  of the O'Briens of Thomond settled from time to time in the county Waterford, and there held large tracts of land. We can trace the Ballyetragh branch as far back as Anthony O'Brien, of Comeragh, who in 1549 obtained a pardon from the Government: and who was contemporary with Connor, who is No. 121 on the same pedigree. In 1598 Terlagh O'Brien, son of said Anthony, lived in Comeragh  Castle, at the foot of the Comeragh Mountains; in 1619 that Castle was unsuccessfully besieged by eleven knights of the Furlong family. According to the "Book of Survey and Distribution" for the co. Waterford, Derby O'Brien, son of said Terlagh, was the proprietor of Comeragh, in 1641; and, according to Exchequer Inquisitions taken at Dungarvan, on the 9th October, 1656, said Derby O'Brien  was dead in that year.
After a fierce resistance by the five sons of Derby O'Brien, Comeragh Castle was taken by Cromwell, who hanged four of them; the fifth son, John, of Kilnafrahane, escaped to the sea‑coast and settled near Helvick Head. From said John are descended the O'Briens, of Ballyetragh, co. Waterford.
Commencing with Anthony, and with (121) the number of Connor, both above mentioned, the following is the pedigree of this family:
121. Anthony of Comeragh, who was pardoned by the Government in 1549, had:
122. Terlagh, living in 1598, who had:
123. Derby, of Comeragh Castle, living in 1641, who had:
124. John, who had:
125. Matthew, who had:
126. John, who had:
127. Matthew, who m. Mary, dau. of Mr. Keating, of Tubrid, co. Tipperary, one of the family of the eminent Irish historian Jeoffrey Keating. One of that lady's brothers was Parish Priest of Kilgobinet; it was, therefore, that this Matthew O'Brien came to reside at Ballyetragh, near his brother‑in‑law. Of the issue of that marriage was:
128. Michael, who m. Miss Rogers, of Coolroe, co. Waterford (whose family is mentioned in Smith's History  of Waterford, as among the Landed Gentry residing near Suir), and had four sons and five daughters:
I. Pierse, of whom presently.
II. Matthew Rogers O'Brien (d.), of Coolroe, above mentioned; who m. Ellen, dau. of James Connolly, Barrister‑at‑Law (a descendant of the famous Harry Flood), and had three sons and three daughters:
(All three living in 1884).
The daughters were:
I. Anne, who m. Doctor Walsh, of New York.
II. Helen, who m. Doctor Dutt, of Calcutta.
III. Mary, who (see the "Ryding" pedigree, infra), m. Frederick Ryding, L.D.S., R.C.S.E.; both living in 1887.
III. Thomas, of Kilnafrahane; third son of Michael.
IV. Michael: the fourth son. The five daughters of Michael (No. 128) were:
I. Mary, who m. M. Hudson, Esq.
II. Anne, who m. a Mr. Barry.
129. Pierse O'Brien, of Ballyetragh, co. Waterford: eldest son of Michael, living in 1887; is the present representative of the Ballyetragh family.
 Branches: Of those branches we find that Daniel O'Brien, of Ballyknocke, in 1632, was the son of Teige (d. 1620), who was the son of a Donagh O'Brien; that Murtagh O'Brien, of Cottir, in 1641, was the son of Mahon (d. 1623), who was son of a Donagh O'Brien; and that Donagh O'Brien of Jemybrien, in 1641, was the son of a Brian O'Brien. There are several Inquisitions in the Chancery Records for the co. of Waterford, in the reign of Charles I., regarding the O'Briens.
 Comeragh: Salterbridge near Cappoquin, on the river Blackwater, also belonged to this family.
 Derby O'Brien: As this Derby was dead in 1656, it may be supposed that the Mary Brien of Kilcomeragh, who was transplanted from the co. Waterford, in 1653, was his wife. Among the O'Briens who in that year were also transplanted from the co. Waterford were Terlagh O'Brien, of Cottin; Donagh O'Brien, of Kilnafahane; and Brian O'Brien, of Ballyathin (or "Boullyattin")‑‑See "Transplanters' Certificates," in the Public Record Office, Dublin; and "Persons Transplanted," in p. 349 of our Irish Landed Gentry when Cromwell came to Ireland. (Dublin: Duffy and Sons, 1884).
 Keating: There were four brothers Keating, all Priests, who had studied at the then famous University of Coimbra, in Portugal. They were near relatives of the Rev. Father Sheehy, of famous memory, who was arrested in the house of Mr. Keating of Tubrid, above mentioned.
 History: Published in 1750.