Genealogy & Research
Explore Your MacCarthy Ancestry
Genealogy lies at the heart of the Gaelic clan system. This section brings the MacCarthy Reagh research corpus together for descendants and serious genealogists, including the family tree, known septs, accepted and disputed pedigrees, archival discoveries, Y-DNA evidence, land records, and collaborative research notes.
The guiding principle is careful evidence. Pedigrees are published only where they have been certified by a competent authority, published by a recognised genealogical authority, or otherwise supported by satisfactory documentary research. At the same time, the Clan acknowledges that many genuine family lines may have lost the records needed to connect them conclusively with a named historical sept. Probable descent should therefore be distinguished from proved descent rather than either dismissed or overstated.
Known Septs and Branches
Clandermond
Descended from Dermod, eldest son of Donal Goth.
Clan Tadhg Ilen / Clan Tadhg Dall
Descended from Tadhg Dall, second son of Donal Goth.
Clan Crimen
Descended from Dermod, a son of Donal Glas.
Sliocht Felim of Gleannachroim / MacCarthy Glas
Descended from Cormac Donn, fourth Prince of Carbery; the chiefs of this sept were known as MacCarthy Glas, Lords of Gleannachroim.
Sliocht Glas of Dunmanway
Descended from Cormac Glas, second son of Felim of Gleannachroim.
Sliocht Dermod of Iniskean / MacCarthy Rabagh
Descended from Donnchadh of Iniskean, seventh Prince of Carbery.
Sliocht Owen
Descended from Eoghan, son of Domnall Riabhach.
Sliocht Cormac na Coille
Descended from Cormac na Coille, son of Domnall Riabhach.
Sliocht Glas of Ballinadee
Descended from an illegitimate son of Domnall Glas, sixth Prince of Carbery.
MacCarthy of Springhouse
Descended from Owen of Springhouse, a younger son of Donal na Pipi.
McCarthy Reagh of Drinagh
A modern research designation for a family branch closely associated genetically with MacCarthy Tullagh and linked by ongoing research to the later chiefly family.
McCarthy Tullagh
A branch genetically close to the Drinagh line.
MacCarthy Farshing
A distinct Y-DNA-associated branch in ongoing research.
MacCarthy Downing
A recorded branch in the Clan research corpus.
MacCarthy Tallin / Talún
A recorded branch with distinct Y-DNA findings.
McCarthy Mountain of Hare Island
A local family agnomen preserved in the research archive.
The Chiefly Lines
Several senior post-medieval lines can be distinguished within the surviving genealogical record. The Chiefly House regards the line descending from Cormac, Lord of Carbery, and Lady Eleanor MacCarthy of Muskerry as extinct in the male line and likewise regards the documented male lines of Finghin of Banduff as extinct. Other MacCarthy Reagh families may nevertheless survive whose connecting documentary pedigrees have not yet been recovered.
A central research correction concerns Finghin MacCarthy Reagh, born in 1625. Older published pedigrees placed him as a son of Cormac. The 1636 Inquisition post mortem for Domhnall MacCarthy Reagh records Cormac as Domhnall's son and heir and gives Cormac's age as sixteen at the time of his father's death. Since Finghin was born in 1625, he cannot have been a son of that sixteen-year-old Cormac. The surviving evidence therefore places Finghin among the other sons of Domhnall, correcting a genealogical error repeated in later sources.
Springhouse is a junior branch descending from Owen of Springhouse, a younger son of Donal na Pipi. Louis Lainé's published genealogy records a large family, including Donogh MacCarthy and his children; the French comital line descending through Justin MacCarthy Reagh eventually became extinct in 1906 with Nicholas Francis Joseph, fourth Count MacCarthy Reagh of Toulouse. A possible senior line through a Jeremiah who may have been a son of James MacCarthy remains unproven because the early twentieth-century family research did not provide the source citations necessary to verify it.
A major modern research project concerns the McCarthy family of Cashloura in Drinagh Parish. Collaborative work among distant cousins, family records, archival research, and Y-DNA has been used to connect this line to Finghin MacCarthy Reagh, born 1625 and died 1676. In abbreviated form, the descent is as follows:
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Domhnall na bPíopaí (1535-1612), 17th Prince of Carbery and Chief of the Name, married Margaret FitzGerald.
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Cormac MacCarthy Reagh (died 1602), married Eleanor FitzGibbon, daughter of the White Knight.
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Domhnall MacCarthy Reagh (died 1 August 1636), married Lady Ellen Roche of Fermoy.
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Finghin MacCarthy Reagh (1625-1676), styled in French records as comte de Mac Carthy-Reagh, married Lady Mary in France.
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Dermot MacCarthy Reagh (1658-1728).
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Donal I MacCarthy (1690-1758), married Kate O'Driscoll.
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Donal II McCarthy (born 1730), married Anna McCarthy Reagh of Gortnascreeny on 9 April 1761.
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Daniel McCarthy (1762-July 1825), married Catherine O'Hurley on 8 January 1785.
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Charles McCarthy of Cashloura (born circa 1785), married Honora McCarthy Reagh of Gortnascreeny, a great-granddaughter of Finghin of Banduff.
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James McCarthy (born circa 1813), married Mary Ross of Dromcorragh on 12 February 1839.
A fuller sourced history of the Cashloura family supports this reconstruction and makes the branch an important example of how documentary genealogy and genetic evidence can be used together.
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Y-DNA and the Clan
Y-DNA is passed from father to son and can preserve a record of paternal-line mutations across many generations. Single-nucleotide polymorphisms, or SNPs, can therefore help distinguish branches of a surname group when documentary records are incomplete. Y-DNA does not replace genealogy: it cannot by itself identify a historical ancestor, prove a title, or reconstruct every generation. Its strength lies in testing whether paternal lines share a common ancestor and in helping place branches relative to one another.
ZS4598
MacCarthy Glas / Ciaragh
Associated with Donal Goth and the MacCarthy Glas/Ciaragh branch.
BY7779.2
McCarthy Tullagh
A sub-branch closely related to the Drinagh MacCarthy Reagh.
BY74588
McCarthy Farshing
Associated with Daniel McCarthy Farshing, born circa 1730 at Gortnasowney.
A10926
McCarthy Tallin / Farshing
Branch marker in the research tree.
BY140627
McCarthy Rabagh
Associated uniquely with the Rabagh branch.
FGC1058
McCarthy Tallin
A marker associated with the Tallin branch.
BY7779
McCarthy Reagh of Drinagh
Associated with the Drinagh and Tullagh cluster; Clan research connects this line to Donal na Pipi.
ZZ50
MacCarthy Reagh
A marker downstream of the early MacCarthy Reagh princely line, associated with descent from Donal Caomh, second Prince of Carbery.
Taken together, these results support a provisional model of seniority among surviving or extinct branches: the Cormac-and-Eleanor chiefly progeny; a Kilbrittain-related group including modern Vancouver, Colorado, and Oak Bluffs families; the extinct Toulouse comital line; Springhouse; Farshing and Tallin/Talún; and the MacCarthy Rabagh. Because the Y-DNA tree continues to develop, this hierarchy remains a living research model and should be read as provisional.
Research Library & Sources
The following sources and research tools are recommended for the study of the MacCarthy Reagh, the wider MacCarthy family, the history of Carbery, Gaelic genealogy, Brehon law, and traditional Irish culture. Historical pedigrees should be read critically and, where possible, compared with contemporary documentary and genetic evidence.
Louis Nicolas Hyacinthe Chérin — Généalogie de la Royale et Sérénissime Maison de Mac-Carthy / Chérin Collection. Eighteenth-century genealogical material preserved in the Bibliothèque nationale de France, including the certified MacCarthy genealogy and supporting documents concerning the MacCarthy Reagh and other branches of the family. View the manuscript on Gallica (BnF)
MacCarthy Reagh Pedigree, 1607. An early seventeenth - century pedigree of the family, produced shortly after the surrender of Carbery and preserved among Irish heraldic records. View the 1607 pedigree
John O'Hart — Irish Pedigrees; or, The Origin and Stem of the Irish Nation, 5th ed. (1892). Includes the well-known MacCarthy Reagh pedigree. Valuable as a historical compilation, although portions of the later genealogy have subsequently required correction. Read the MacCarthy Reagh pedigree
Samuel Trant McCarthy — The MacCarthys of Munster: The Story of a Great Irish Sept (1922). A substantial history of the MacCarthy family, including dedicated chapters on the MacCarthy Reagh Princes of Carbery, Springhouse, Toulouse, and other branches. Read the 1922 edition
P. Louis Lainé — Généalogie de la Maison de Mac-Carthy anciennement Souveraine des Deux Momonies ou de l'Irlande Méridionale (Paris, 1839). An important French genealogy of the MacCarthy family, particularly valuable for the MacCarthy Reagh, Springhouse, and continental branches. Read the CELT edition, University College Cork
Sir Bernard Burke / A. C. Fox-Davies — A Genealogical and Heraldic History of the Landed Gentry of Ireland (1912). Includes entries for MacCarthy families including Srugrena Abbey and Carrignavar. View the 1912 Landed Gentry material
John O'Donovan — “Pedigree of Mac Carthy of Dunmanway, Chief of Gleann-a-Chroim.” Particularly useful for the history and genealogy of the MacCarthy Glas branch; published with O’Donovan’s historical material. Read the digitised pedigree
Genealogical Office — Registered Pedigrees. The National Library of Ireland preserves numerous pedigrees relating to the MacCarthy family, including MacCarthy Reagh, MacCarthy Mór, Dunmanway, Carrignavar, Muskerry, and other branches. NLI Registered Pedigrees, Vol. 22
MacCarthy Reagh Papers, 1584–1786 — National Library of Ireland, MS 50,561. A dedicated collection of family papers containing wills, deeds, property records, and testimonies concerning MacCarthy Reagh lineage in Ireland and France. Browse the MacCarthy Reagh Papers
Irish Record Commission — Inquisition Post Mortem, 1636. The inquisition recording the death of Donal/Daniel MacCarthy Reagh and identifying his son and heir Cormac as sixteen years old. This evidence is important in correcting the traditional pedigree of Finghin MacCarthy Reagh (1625–1676). View the original record through the Virtual Record Treasury of Ireland
Genealogical Office — Funeral Entries, Vol. 9, 1640–1663, GO MS 72. Heraldic and genealogical funeral records preserved at the National Library of Ireland and used in research concerning the seventeenth-century MacCarthy family. National Library of Ireland catalogue record
Genealogical Office — Grants and Confirmations of Arms, Vol. P, 1932–1940, MS 111f, fol. 125. Contains the 17 September 1937 confirmation of arms to Francis Leader MacCarthy, with a recorded claim of descent from Donal Reagh MacCarthy of Kilbrittain Castle. National Library of Ireland catalogue record
MacCarthy-Willis-Bund Pedigree, 1937. The pedigree associated with Francis Leader MacCarthy-Willis-Bund and certified by the Norroy and Ulster King of Arms. It preserves an important twentieth-century version of the chiefly genealogy, although its placement of Finghin (1625–1676) has since been corrected. View the 1937 pedigree
Certificación de Armas y Genealogía. Modern certification of the arms and pedigree of Sir Evan Patrick McCarthy by the Chronicler of Arms of Castile and León, incorporating corrections to the later MacCarthy Reagh pedigree. View the certification
“Donogh McCarty Reagh” of Dromcorragh, 1663. A surviving bond-index record concerning a Donogh McCarthy Reagh of Dromcorragh in Caheragh parish. View the record
Florence McCarthy of Dromcorragh, 1805. A deed record documenting Florence McCarthy in connection with land at Dromcorragh. View the deed extract
Evan McCarthy — “Update to Finghin's Origins” (2023). Research note explaining the documentary correction to the traditional parentage of Finghin MacCarthy Reagh (1625–1676). Read the research note
Tithe Applotment Books, 1823–1837 — National Archives of Ireland. A searchable pre-Famine record of agricultural occupiers, useful for locating MacCarthy/McCarthy families by surname, parish, and townland. Search the Tithe Applotment Books
Griffith's Valuation. The mid-nineteenth-century Primary Valuation of Ireland, searchable by occupier, landlord, parish, townland, and county. Search Griffith's Valuation
Virtual Record Treasury of Ireland. A major digital resource reconstructing records lost with the destruction of the Public Record Office of Ireland, including material used in MacCarthy Reagh research. Visit the Virtual Record Treasury of Ireland
National Library of Ireland. The principal repository for many of the Genealogical Office manuscripts, pedigrees, funeral entries, heraldic records, and MacCarthy Reagh family papers cited in Clan research. Search the National Library of Ireland catalogue
Gallica — Bibliothèque nationale de France. The BnF’s digital library, containing the Chérin genealogical papers and other French material relating to the MacCarthy family. Search Gallica
Placenames Database of Ireland — Logainm.ie. An authoritative resource for Irish and English forms of townlands and other placenames, including historical spellings and mapping. Search Logainm.ie
Statue of Liberty–Ellis Island Foundation Arrival Records Collection. A useful immigration database for tracing MacCarthy and McCarthy emigrants to the United States. Search the Arrival Records Collection
McCarthy Surname Study — FamilyTreeDNA. An international Y-DNA project seeking to identify paternal relationships, septs, sub-septs, agnomina, and characteristic genetic markers among men bearing MacCarthy, McCarthy, and related surnames. Visit the McCarthy Surname Study
McCarthy Surname Study — Y-DNA Results. Searchable genetic results and haplogroup information underlying much of the Clan’s modern Y-DNA analysis. View the Y-DNA results
The McCarthy Surname Y-DNA Study Scrapbook. Supplementary phylogenetic trees, pedigrees, articles, bibliographies, and genetic-genealogy research maintained by the McCarthy Surname Study. Visit the Y-DNA Study Scrapbook
Eugene O'Curry — On the Manners and Customs of the Ancient Irish. A foundational nineteenth-century study of early Irish society, institutions, learning, material culture, and custom. Read the digitised work
Laurence Ginnell — The Brehon Laws: A Legal Handbook (1894). An accessible historical introduction to the institutions and principles of early Irish law. Read The Brehon Laws: A Legal Handbook
John O'Donovan, ed. — Leabhar na gCeart / The Book of Rights (1847). A bilingual edition of the medieval Irish text concerning the rights, privileges, stipends, and obligations of Irish kings and kingdoms. Read The Book of Rights
P. W. Joyce — “Dress and Costume in Ancient Ireland,” in A Smaller Social History of Ancient Ireland (1906). A useful overview of clothing and dress in historical Gaelic Ireland. Read “Dress and Costume in Ancient Ireland”
Clans of Ireland — “Traditional Attire.” A modern study and bibliography concerning the clothing of Gaelic Ireland, with discussion of the léine, brat, brooches, textiles, dyes, and social distinctions in dress. Read “Traditional Attire”
Irish Script on Screen — Dublin Institute for Advanced Studies. A major digital repository of Irish manuscripts, including material originating in the learned and legal traditions of Gaelic Ireland. Visit Irish Script on Screen
The Brehon Academy. Educational articles, courses, and audiovisual material devoted to Brehon law, Gaelic custom, society, kinship, and culture. Visit the Brehon Academy
John Biggins — The Brehon Lawyer. An independent legal-history resource devoted to early Irish law and its historical and legal context. Visit The Brehon Lawyer
Proinsias Mag Fionnghaile — “Traditional Irish Clothing in the Gaelic Period.” A presentation on traditional Gaelic dress and its historical forms. Watch the presentation
Medieval Dead — “Galloglass: Warlords of Ireland” (Season 3, Episode 4). A documentary treatment of the Norse-Gaelic galloglass tradition using historical, archaeological, and forensic evidence. View programme information
Ancestral Findings — “Why Irish Genealogy Is So Difficult.” A concise introduction to common difficulties in Irish genealogical research, including lost records, surname variation, migration, and dispersed archival holdings. Watch the video
Editorial note: This consolidated list is designed for use on the Clan MacCarthy Reagh website. It distinguishes historical and archival sources from modern databases, genetic genealogy tools, and supplementary cultural resources.
Contribute to the Research
Family research often survives outside public archives: in Bibles, letters, estate papers, photographs, funeral cards, diaries, oral traditions, DNA projects, and documents held by distant cousins. The Clan invites contributors to share material that may help reconstruct the families of Carbery. Submissions should include the source, date, provenance, and - wherever possible - images or citations that allow the information to be independently checked.
If you have a pedigree, family paper, DNA result, ancestral townland, or historical record connected with the MacCarthy Reagh or the families of Carbery, contact the Chancery at: