Klyosov and Conroy have conducted an interesting study into the origins of R1b-M222+ ydna. This study seems to fit with my understanding that the Irish M222 is from the father or grandfather of High King (Ard Ri) Niall of the Nine Hostages. This study demonstrated that the M222 of Ireland and Scotland comes from this origin.
However the early ancestor of ydna R-M222 is in Devon or South West England (which was British not English in those days) around 400-500 years earlier according to the study. This would confirm my understanding that Niall is a descendant of the family of St Joseph of Arimathea who lived in this region of South West England. The first member of the family to have R-M222+ may have been Joseph himself or his son Gilead ben Joseph (Josephes/ Galahad). Joseph's older brother Nathan (Tasciovanus/Tenaufen/ Nascien) a British King was of R-L21 and the male line ancestor of the Babylonian Exilarchs, the Royal House of Stuart and the House of Oldenburg among other Royal Houses in Europe.
It was St Joseph's grandson Nathan the Red (Ruada Nectan) as a Jewish Christian Exilarch (Ros Glas/ Rosh Galuta) that took M222 firstly into Ireland- this was the time of the bottleneck period connected by the study to Leinster. His son Phares (Feradach) as the Scottish Jewish Christian Exilarch took this R1b-M222 into central Scotland (Galefort/ Camelon).
When this Exilarchy in Ireland became syncretized with paganism around the time of Conn of the Hundred battles they became secular rulers (kings). They became the Rulers of areas of Ireland and it is said according to the old tales that Niall ruled over both Ireland and Scotland and it is from this period that M222 started its great expansion. The M222 ydna in South West Scotland and of the Scottish Royal House of Dunkeld/Atholl coming from the Irish M222 of Niall's kin.
Here are the conclusions of Klyosov and Conroy's study:
"...Based on our data analysis and discussion, M222 is likely to have arisen in South Western England. The M222 bearers of Devon ancestral origin clearly have the oldest common ancestor of M222 followed by other regions/countries, which are practically impossible to reliably resolve in terms of the “age” of M222 common ancestor. However, cross-analysis of lineages shows that the Irish M222 could have arisen immediately after the English M222, but due to a possible bottleneck of the population they started to expand only in the middle of the 1st millennium CE.
Thanks to the recently developed methodologies of DNA genealogy, based largely on the DNA sequencing and the apparatus of chemical and biological kinetics, as well as to hard work of administrators of FTDNA Projects (see Acknowledgments below) collecting and publishing haplotypes, we were able to do the work with 67 and 111 marker haplotypes, which greatly improved resolution of the haplotype branches and other results compared with those done with shorter (such as 17-marker haplotypes).
The obtained data suggest that the M222 lineages in The Isles likely originated in Devon, England and either from there to Leinster, Ireland and then to South West Scotland. In Leinster, the Dumnonii - known as the Fir Domnann or Laigin - conquered all of Western Ireland, Connacht, and birthed the dynasty known as the Connachta, which in turn gave rise to the Uí Néill dynasty of Northern Ireland.
In overall terms it would seem the rank ages of R-M222 in the Isles we could suggest as follows: (a) Devon, England, (b) Leinster, Ireland (c) Central Scotland, (d) North Midlands, Ireland (e) Connacht, Ireland (f) Northern Ireland (g) Wales (h) South West Scotland..."