April 2025

Aligning the results of the DNA study with historical records and genealogies has enabled the larger genetic groups on the project to be defined by geographic location and pre-Norman Irish dynastic associations, as follows:

R-FGC11134 … BY12234 (Bréifne/Connachta)

R-FGC11134 … BY23574 (Eóghanachta)

R-FGC11134 … FTA26679 (Eóghanachta)

R-FGC5494 … CTS2457 (Bréifne/Connachta/Oirghialla)

R-L513 … BY2631 (Breifne/Oirghialla)

R-L513 … FGC9811 (Breifne/Oirghialla)

R-L513 … BY4794 (Breifne/Oirghialla)

R-Z253 … FT212775 (Dál gCais)

R-Z253 … FT159792 (Dál gCais)

R-Z253 … FTB96301 (Dál gCais)

R-Z255 … BY2849 (Laighean)

Among these groups, it is likely some of the Dál gCais, whose clans are registered collectively with the Clans of Ireland, descend from Scanlan Mac Giolla Phádraig of Ossory, the chieftain of various annalistic records and pedigrees. The clan can be read about in the article Mac Giolla Phádraig Dál gCais: an ancient clan rediscovered.

Also ancient and registered with the Clans of Ireland are the Bréifne/Connachta clans (represented by RFGC11134 ... BY12234 and R-FGC5494 ... CTS2457), who are currently defined as Ó Maol Phádraig Bréifne, who are the discussed in two articles Ó Maol Phádraig: the name, the people, and the clans Part I and Part II.

The complex and varied origins of those Fitzpatricks who trace to Breifne/Oirghialla are demonstrated by the fact there are a further three Fitzpatrick clans of that region who are of haplotype R-L513. One of those clans is somewhat associated with the surname Maguire and may represent descendants of Giolla Phádraig of Fermanagh, of the Maguires.

There is also complexity in the origins of Fitzpatrick clans of the deep south. It is likely the numerous Fitzpatricks who are under haplotype R-FGC11134 ... CTS4466 are either Ó Maol Phádraig Eóghanachta or Mac Giolla Phádraig Eóghanachta.

There is no small intrigue associated with Fitzpatrick clans who appear to have their origins in Ireland after the Norman invasion. The Fitzpatrick clans of J-M172 … FTA78391 and R-FGC5494 … A1488 are jointly registered with the Clans of Ireland as Fitzpatrick of Ossory. The ancient origins of J-FTA78391 Fitzpatricks are unknown, but based on ancient DNA samples from modern-day France and Sweden, as well as surname associations, the pre-Irish origins of haplotype R-A1488 appears to have been among Viking and, later, Norman families. Notably, R-A1488 Fitzpatricks have direct patrilineal connections with Branan-like surnames and the Dalton surname - those names were previously de Braham and de Antonē, and those families arrived in Ireland shortly after the Norman invasion, later adopting Irish-surname forms.

In addition to the larger groups mentioned, there are several mid-sized genetic groups that are enjoying increasing definition; these include clans haplotypes R-M222, R-U106, and I-M223, of whom we aim to gain a greater understanding.

And then there are many smaller groups and individuals with no close Y-DNA matches to any other Fitzpatricks; they include men identified under various R1b, D, E, I and Q haplotypes.