The Galician annals are written in Greek ~ which appears to have been the "lingua franca" of its day. They claim to extend all the way back to 700 BC.
That's when the Gaelic speakers arrived in NW Spain and began taking the place over.
No doubt the local Basque population were startled with this intrusion, but the technologically superior folks who'd been sailing the Mediterranean and Black Seas for several hundred years since they'd been driven out of the Danube region had absolutely no problem conquering local tribes and imposing their language and religion on them.
Shortly after 700 BC these people invaded Ireland and took over (calling it Scota after their chief goddess). They called themselves Ir but had a three brothers tradition.
So, if the Annals are legitimate and the record is correct, Mediterranean dwellers invaded Basque country about 700 BC, raped the women, enslaved the men, and changed the genetic heritage of the locals. Later on that same mix was taken to Ireland in yet another conquest and had the same effect. The result was the Basque and Irish populations of today appear to be essentially identical (with, of course, a touch of that African lineage here and there, but not so's you'd notice it unless you knew where to look).
The Y chromosomes simply disappeared into whatever hole male slaves disappear into and were no longer biologically significant in the Basque population.
Recalling that children learn their mother's language, we can readily see that the Basque language was able to survive through the survival of female lineages in the more isolated parts of the Basque country, but this did not happen in the area totally dominated by the Gaelic speakers just to the West of today's Basque speaking areas.
I'm beginning to think the Annals that survived in Galicia are probably legitimate, as are the later documents about King Arthur and Merlin.
So is the Basque language similar to any other language out there?