Were the first Bell Beaker folks on the British Isles actually Irishmen?
No, but their genomes were more like the modern Irish genome than anyone else's. They may have been the first Insular Celts or some Early/Archaic type of Celtic which would be technically Pre-Celtic.
R1b-L21 phylogenetic tree, particularly DF13 branching, shows very early expansion with sustained growth until today. Is it possible this represents the Milesian legend. It is difficult to line up the branching with the sons and grandsons of Mil and Mil doesn't appear to be from Spain but the Irish founding story may represent ancient clans or tribes.
Can the old Irish texts like the Irish Annals and Book of Invasions be useful in understanding Irish, Scottish and Welsh families and their paternal lineages? Perhaps, there is a lot of detail in the old Irish texts. Much of it is confusing and conflicting but with all of that detail there probably are valuable facts too.
We may be like miners sifting through the dirt and fool's gold hoping to find the gold nuggets.
Please post any theories you have here. The more specific the better, but please cite your sources and reasoning.
Maps of Ireland history.
You can find English versions of the Irish Annals here.
Lebor Gabála Érenn (Book of Invasions)
The earliest historical document with insights into the Irish may actually by "the venerable" Bede.
Happy St. Patricks Day!
I have a dozen other charts on this topic posted on https://www.facebook.com/groups/R1b.YDNA