As some of you may already know, and as I detail on our surname project webpage, I'm not a big fan of the commonly repeated claim that the Curley name derives from the Irish name MacThoirdealbhaigh, as it contradicts the existing documentation. As of this morning, I have a new favorite among my theories regarding the name origin. I recently noticed some intriguing patterns that I wanted to put out there for public consumption.
For some time I've been aware that there are some native Irish Curleys who use the Irish spelling "Mac Oirealla" for their name. Up until recently, I've never given this name spelling much consideration, assuming it was possibly just a modern phonetic translation into Irish from the English version of the name. But there are some very interesting patterns regarding this version of the name that demand closer consideration.
Oirealla is an English spelling of the 8th century kingdom of Airghialla, which was roughly located in the modern counties of Louth, Monaghan, Armagh, Fermanagh, Tyrone, and Derry. For more information on the Airghialla kingdom, see this Wikipedia page: http://en.wikipedia.org/wiki/Airg%C3%ADalla
Consider the earliest recorded English spellings of the Irish Curley family from the 16th century: MicKurylly and M'Kirilie. Phonetically, these names are closer to MacOirealla than to MacToirdealbaigh or its common English translation of MacTurlough.
Griffith's Valuation reveals a concentration of Curleys in counties Louth and Monaghan, spreading inland from the city of Dundalk, as you can see on the map I have on our website: http://curleysurname.weebly.com/irish.html. This population lies neatly within the kingdom of Airghialla.
Our project currently has 3 genetic groups with lineages that trace to Irish Curleys. It is probable that one of these groups has an intact lineage descending from the surname progenitor, while the other two groups have been affected by non paternal events. This sort of fragmentation is typical of surname lineages which are hundreds of years old. Of these three genetic groups, two of them look like possible candidates for the original MacOirealla lineage.
"Irish Curley 2 - Counties Roscommon and Galway" - This group currently has two members, one of whom probably traces to the Suck Valley area along the border of counties Galway and Roscommon. This group's DNA matches with individuals from Scotland and England.
"Irish Curley 3 - Counties Galway and Sligo" - This group contains individuals who trace to county Galway and Sligo. This group belongs to the M222 genetic subclade, which is native to Northern Ireland and Scotland, including the area of Oriel.
I've heard oral traditions that the Roscommon/Galway/Westmeath Curleys were originally from the north, and moved south when their land was confiscated during the Plantations. This story corresponds very neatly with the population distribution we see for the Curley name. The small population cluster in the north near Dundalk reflects the original location of the family. The larger populations around Athlone and westward into Galway reflect those members of the family that were forced from their homes and resettled in the south.
So, to summarize my theory: the Curley name derives from the ancient kingdom of Airghialla, with a modern English spelling of Oirealla. Our DNA group "Irish Curley 2" or "Irish Curley 3" may be descendants of this ancient lineage. The other two Irish Curley lineages probably share the same name lineage, but the genetic lineages have been broken by non paternal events.
Test results of our new project members may confirm a connection between northern Curleys of the Airghialla area and southern Curleys of the Roscommon/Galway area. Please keep in mind that this theory is brand new, and hasn't had any time yet to be nit picked and torn to pieces. So it will need some time to settle and be confirmed or rejected. But right now I feel very good about it, and it's my leading theory by a wide margin. Of all the various theories regarding the family origin, this is the first one that I'm comfortable with. Unlike previous theories, this one is fully consistent with all the historic documentation and genetic evidence.
To help confirm this theory, it would be great to have a DNA test from a Curley of the Louth or Monaghan area. If anyone has any connection to such a Curley, please send them my way: firstname.lastname@example.org. I'll sponsor a 111 marker test for any Curleys that are native to this area. If we get a DNA match from this area to our current "Irish Curleys 2" group, that would be strong evidence in support of the theory.
Please note that the project webpage is not yet fully updated with this new information. I'll be updating it as soon as possible.