The reason I sponsored this test was that I suspected the Group 4 Galway Curleys were a very old lineage, possibly the original lineage of the family. My hypothesis, based on documentation, was that the family had started out in the Oriel area of Monaghan/Louth counties around the 15th century. In the 16th century some of the family migrated to the Roscommon area around Ballymacurly and then expanded south and west into Galway and Athlone.
This Dundalk test appears to confirm this hypothesis! The tester descends from three known generations of Dundalk Curleys. His DNA is a distant match to the Group 4 Galway Curleys, having the STR values of DYS449=27 and DYS570=15 which are unique to this group. This confirms that the Dundalk Curleys are distantly related to the Group 4 Galway Curleys.
The estimated distance to the shared ancestor of this group is centered at ~17.25 generations. Multiplying by 30 years per generation gives 517 years, which puts the shared ancestor at around 1450 AD. This date fits perfectly with the documentation. The Annals of Ulster document a Curley in the Oriel area in 1447 AD.
The DNA match is strong evidence that Group 4 is the original lineage of the Irish Curleys. The family started out in the Oriel area, then one branch of the family migrated to Roscommon, as reported by oral tradition and supported by documentation. Most modern Curleys descend from the Galway/Roscommon lineage. But the Oriel Curleys of the Louth and Monaghan area represent the original location of the family. Both lineages share a common ancestor from around the 15th century, as well as pre-surname matches to the Oriel area. This not only confirms the documentary evidence, but also supports the etymology of the Curley name originating from MacOirealla/MacOirghaillaigh, with this name being connected to the modern place name Oriel and the original kingdom name Oirghialla, where counties Louth and Monaghan now lie.