McCarthy Surname Study- Background



Cremeans, Cremeen, Cremin, Crimeen, MacArthy, MacCarthy, McAuliffe, McCarter, McCarthy, McCarty, O'Cremin


McCarthy/MacCarthy is one of the most common surnames in Ireland today and is prevalent throughout Counties Cork and Kerry.  Through migration over the past four hundred years, McCarthys now reside in many countries throughout the world.

In October 2002, the McCarthy Surname Study was started through Family Tree DNA, Inc. (FTDNA) of Houston, Texas, U.S.A. The McCarthy Surname Project will attempt through Y-DNA analysis to compare individuals with surnames common to the McCarthy Clan and to identify any genetic markers which might single out groups of McCarthys or their immediate predecessors.  These surnames include but are not limited to the following: McCarthy, MacCarthy, Macarthy, McCarty, and McCarter.

Apart from facilitating family connections among McCarthys throughout the world, it is hoped to identify the yDNA profiles associated with both the leading families of the various MacCarthy septs (Mór, Reagh, of Muskerry, of Duhallow, Glas etc.) identifiable in the ancient histories as in use from ca. 14th century and more recent agnomens adopted to distinguish one McCarthy family grouping from another e.g. Cnoic, Crimeen, Cruig, Daunt, Farshing (Fairsinn), Guidagh (Gaibhdeach), Meenig (Muineagh), Norsa, Rabagh, Sowney, McAuliffes and O'Crimeens (or variants of these) are also welcome to join the project if they can trace Munster origins, since these surnames are claimed to have origins in branches of the McCarthy family.

As more data becomes available, the findings of this and other projects for surnames which the ancient histories and genealogies indicate derive from first millenium A.D. Eóghanacht origins can be compared with the content of these texts

This webpage contains the following articles:

  • McCarthys in Antiquity

  • Subclades of R-L21

  • References for McCarthy Genealogists


Original - 10 May 2010.
Last updated – 27 July 2013.

1        Introduction

The following is written by an amateur genealogist and historian with a view to providing useful information for members of the McCarthy Surname Study, some of whom may be more knowledgeable, some beginners. The author will be happy to review, and correct where justified, any perceived errors. A modicum of understanding of DNA diversity is assumed: please refer elsewhere on the FTDNA website or to the most helpful ISOGG (International Society of Genetic Genealogy) website for the science of SNPs (Single Nucleotide Polymorphisms), the phylogenetic tree, STRs (Short Tandem Repeats), DYS (DNA y-chromosome Segment) values / alleles, the distinction between a haplogroup (of which clade or subclade are used to indicate subdivisions in the following) and haplotype, and their use in genealogy.

2        Brief history

The earliest evidence of homo sapiens in Ireland is from ca 8,000 B.C, when it is believed he entered present day Co. Antrim from south-west Scotland, either by boat or via the landbridge still remaining as the last ice age closed and the sea levels were still rising.  Throughout the Mesolithic and Neolithic periods (ca. 8,000 - 2,000 B.C) it seems probable that the inhabitants of Ireland were, as those of Britain, the descendants of those who had retreated towards the Iberian, in particular, and Italic peninsulas during the last Ice Age and the peoples who already occupied these warmer climes, along with any new waves of migration from south-east Europe. YDNA haplogroups E1b1, I1, J1 and J2 could have abounded. Megalithic tombs were rare in the extreme south of Ireland, suggesting that the south of Munster was more thinly populated than the north in the Neolithic Age.

By the beginning of the Bronze Age, however, if not well before, the first carriers of yDNA haplogroup R (in the form of R-M269) were reaching the Atlantic shores of Europe at the end of their centuries- or even millennia-long trek from Anatolia and the Caucasus.  One of its most frequently found subclades in Ireland, that of the SNP R-L21, is believed to have originated in the Rhineland ca. 2,000 B.C. The haplotype associated with this SNP, or those in its lineage immediately preceding it, is known as the Atlantic Modal Haplotype (AMH). The progeny of the “father” of R-L21 came to dominate the tribal lands of, Gaul, Britain and Ireland. The discovery of rich copper deposits in south-west Munster increased the influx of migrants and traders into this region during the Bronze Age, and with them, by whatever route, no doubt came the expanding family of R-L21 along with other haplotypes to be found in the areas of their provenance, the trickle of newcomers from Britain and Continental Europe continuing through the Iron Age, the Viking invasions, and up to and beyond the 12th century A.D. Norman invasion, each new arrival being assimilated into Munster culture and society.

The most difficult aspect of Irish genealogy for many is the lack of parish records much before 1815 in rural areas and the later 1700s in the major towns. However, although following a paper trail back through the 18th century may be impossible for many, what lies beyond is a unique store of genealogical information stretching back many centuries. It was the custom of the peoples who occupied Ireland 2,000 or so years ago to designate a member of each community (or “tribe” or “family”) who would learn, remember and recite its genealogies. Early in the first millennium, these began to be written down. In due course the earliest writings were lost, but successive copies retained the information, albeit flavoured with mythology, distorted by inventiveness or corrupted by political correctness. Certainly from the time of early Christianity in Ireland (the 5th century A.D.), when monks began to take on the role of the scribe, the genealogies were woven with biblical connections, placing them in a context which tied together all strands of known history. But whether fact or fiction, we do have a lineage claimed to have produced the leading McCarthy families and which goes back before these earliest written genealogies. Written sources from about the 12th century onwards indicate that this McCarthy family derived from the Eóghanachta of southern Ireland, who are claimed to have also spawned the McAuliffes (from the above Tadhg), McGillycuddys, O’Callaghans O’Donoghues, O’Keefes, O’Mahonys, O’Sullivans and others. The Eóghanachta took their name from the third century A.D. Eóghan Mór (Eugene / Owen the Great), son of Olioll Olum, King of Munster. However

it is suggested that the identity “Eóghanachta” only came into being following the era of Eóghan Mór’s gt gt grandson (Conall) Corc, in the 5th century A.D. On the death of King Olioll Olum, his kingdom was allegedly divided into Desmond (south Munster), ruled by Eóghan Mór (or a son thereof), and Thomond (north Munster), by Eóghan’s brother, Cormac Cas (from which the term dál gCais, or Dalcassian, is derived to describe its peoples). Most historians now consider this story to have been fabricated at some stage to provide the image of a unified population. Certainly the genetic signatures of those who it is suggested have 'Eóghanacht' and 'Dalcassian' y-DNA haplotypes are not consistent with common ancestry as little as 1,600 years ago.

The supposed relationship of McCarthys to other Munster surnames is typically given as indicated in the following tree, compiled from some of the secondary sources described above.