I hope that I am not revisisting an old topic here, but the question in the title has fascinated me for some time. I do realize that the Celtic cultures have two primary sub-groupings, if understand correctly the current thinking, originating in La Tene and Hallstatt, but apart from that am entirely ignorant. I have heard all sorts of crazy things, even one supposedly popular science program (which I will not name) that went for some odd Himalayan origin point. I know they speak an Indo-European language. Did they have some relationship to the Mesolithic peoples (in that they represent a mixing of I-E with Mesolithic, something I read somewhere a long time ago)? Are the Mesolithic peoples considered the "beaker" peoples? Were they a part of the general I-E migration that settled in La Tene and Hallstatt respectively and developed their cultural identifiers there, or did they arrive with the full cultural complement? Am I getting all of this wrong? Argh, so many questions.

Thanks, and feel free to ignore if this has already been addressed, or is simply too annoying to be addressed.