Res Gestae

Some assert that after the destruction of Troy a few of those who fled from the Greeks and were scattered everywhere occupied those regions, which were then deserted.

But the inhabitants of those countries affirm this beyond all else, and I have also read it inscribed upon their monuments, that Hercules, the son of Amphytrion, hastened to destroy the cruel tyrants Geryon and Tauriscus, of whom one oppressed Spain, the other, Gaul; and having overcome them both that he took to wife some high-born women and begat numerous children, who called by their own names the districts which they ruled.