If that's the case then they might correspond to the Tuatha De Danann of Irish mythology who were supposed to have been the first people to inhabit Ireland (I t

If that's the case then they might correspond to the Tuatha De Danann of Irish mythology who were supposed to have been the first people to inhabit Ireland (I think the Irish have traditionally believed that these were indeed the mound builders). What's confusing is that the article also says they probably arrived from Spain and/or France, which is where the Celtic (and hence Indo-European) Gaels are said to have arrived from much later. Perhaps both groups followed the same route to Ireland at different times ?