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 (Laighin)
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. Also ancient and registered with the Clans of Ireland are the Bréifne/Connachta clan (RFGC11134 ... BY12234), who are currently defined as Mac Giolla Phádraig Ulaidh, and the Mac Giolla Phádraig Laighin, who are R-Z255 ... BY2849.
Notable is the clan who are R-FGC5494 ... CTS2457 because they probably bore a surname now extinct; the Ó Maol Phádraig Bréifne (initially associated with the territory of the Northern Uí Néill, but who moved south into Bréifne, Connachta and Oirghialla) are also registered with the Clans of Ireland. 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 former has the most robust pedigree links to the Barons of Upper Ossory of any Fitzpatrick clan, whereas the latter is likely to include descendants of a lineage of Upper Ossory that included Mac Costigan and Mac Giolla Phádraig clerics.
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. There is a robust narrative regarding some close genetic cousins of R-A1488 Fitzpatrick – those of Branan-surnames who are haplotype R-FGC5494 … BY140757, who probably descend from the de Braham family of Norfolk, that had members (such as Robert de Braham, Sheriff of Kilkenny ca. 1250 AD) arrive in Ireland as part of the de Clare retinue.
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.