Hi
Which is the stronger case for the origin of the Celts ? The Danube region or Iberian peninsula?
I look forward to your feedback.
If you have to have one locus, I think the Danube is a stronger case, because of continuity with Urnfield culture, which is clearly centred on the same region as the Hallstatt but doesn’t have the Atlantic coverage the Iberian hypothesis requires. At least as far as material culture goes. It’s my understanding that the “Celtic from the West” model of Koch is more based on linguistics and there’s an acknowledgement that at least the most characteristic parts of Celtic material culture have a Western source anyway, but the Celtic culture overall is driven by Iberian-originated elites.
However, I personally prefer a synergistic model of a melding of the Atlantic and Urnfield cultures to produce Celtic, so it truly has a dual origin - I think Koch’s model is in its way as simplistic as the old “Out of the East” model.
Although this may be controversial, I think Celtic culture, along with Celtic genes and a pre-Celtic language, can be reasonably extrapolated back to the Bell Beaker culture of 2500 BC or thereabouts, before the Iron Age and even before the discovery of tin in Cornwall. (Of course, Bell Beaker has its own Rhine-Bavaria vs Iberia origin controversy.)
Over a period of many centuries, the British Isles received several waves of adventurers speaking languages related to Celtic. Just as some dialects of present-day English retain features of Old English dialects despite the rise of London Middle English as a standard, so all attested Celtic languages might “descend” from a standard Hallstatt Celtic, but with Goidelic retaining features that predate Urnfield.
In fact, recent genetic studies show a rapid genetic transition after 2450 BC on the British isles, where the native population suffered a minimum replacement of 90 %, higher in some areas. Many of the investigated remains, such as the Aylesbury Archer show dental isotopes consistent with an origin in central Europe.
It seems the Bell Beakers replaced the previous inhabitants almost totally. However, I think most researchers favor a more recent origin for Celtic than the Bell Beakers 2500 BC ?
But what does “origin of Celtic” even mean? The earliest speaker of “proto-Celtic” had a father who spoke a language very close to Celtic! One can speak of the “origin of Kievan Rus” or “the origin of the Islamic Empire”—those were distinctive political entities—but the earliest record of “the Celts” was of a wide-spread but arbitrary grouping of unaffiliated tribes.
Yes, some of those tribes might trace back to Hallstatt, but Hallstatt itself was part of an earlier wide-spread continuum.
That would be more-or-less a logical extension of Koch and Cunliffe’s’s thesis that it originates in the Atlantic Bronze Age culture (given the overlap)- I don’t think that’s controversial. exactly, just not currently the most favoured.
Having just finished Barry Cuncliffe’s Celts: A Very Short Introduction and 3/4 through his Druids intro I have to say that discussions like this one are why I stay here!
I haven’t read enough alternate theories to really say one way or the other but Cuncliffe does make a very cogent argument that the Danube is the headwaters of the Celts.
My personal view is that this quest is kind of like looking for the headwaters of a mighty river; you have to make arbitrary choices about which forks and tributaries are considered critical. That leaves your hypotheses open to dispute! PLease do carry on, I’m loooking forward to hearing more!
Most of the experts on ancient Celtic linguistics are very, very, very skeptical of Koch’s conclusions. Cunliffe’s case is much stronger, but not necessarily tied to language. I think the idea that the Celtic languages spread up the Atlantic coast from Spain, with a push from the economic might of those controlling access to Mediterranean, is a very strong case. The idea that there were Celts in what is now Morocco also seems very likely to me. However, the idea that the shift Indo-European > Italo-Celtic > Celtic occurred in Iberia is a non-starter, especially now that earlier and earlier Celtic inscriptions are being found in northern Italy.
I don’t think there’s enough evidence to say that Tartessian was Celtic.
While hunting for a cite just now, I learned that Jean Manco passed away a few months ago. 
R.I.P. to this wonderful woman who did remarkable work with her studies of European pre-history.
Her top-notch website also went away, but is preserved at the Wayback Machine. Here is her page on “Celtic tribes of Britain and Ireland” though it may not be most relevant for our discussion. It’s not surprising she “agrees with me”:
… since I learned much from her.
She called attention to what she called “the Stelae people” who may need to be fitted into the mystery. The Stelae people seem to have leapfrogged the Rhine by following a southern route: Yamnaya –> Balkans –> Italy –> Iberia –> Armorica. I don’t know if she mentioned them at her website, but pp 161-167 of her Ancestral Journeys (2nd edition) are about them.
For me, a key to understanding Bell Beaker, and its Celtic offspring, is the astoundingly rapid fanout of “the Bell Beaker Y-chromosome”. Clicking to the link, see that, within just 6 centuries, a single man (call him “Mr. P312” or “Bell Beaker Chief”) spawned HundredS of agnatic lines that have survived to the present. Since most of Mr. P312’s sons and grandsons lived near the Rhine, I think he did too, but it’s far from certain. He did have a great grand-son who founded a dynasty in Iberia.
Language shift happens even in genetically homogenous populations, though, so you really can’t mix the argument of “the origin of the Celtic languages” with “the origins of the ancestors of these Celts” unless you have evidence linking the two. The people of Britain might have come to be Celtic speakers via language shift to a prestige language, the same way a lot of us or our ancestors came to English.
By what standard is the answer not the Olduvai Gorge?
Well, I was going to answer “the Celts are natives of Earth”.
But nevermind, I love learning about prehistoric peoples.
But the point is, you have to draw a line somewhere and say that people on this side of the line are Celts, and people on that side of the line are not. You can’t just say “well, the line’s fuzzy; we can’t pin it down”, because that’s at the very root of the OP’s question. Any answer you can give, you’ll find that before that people was there, it was somewhere else, and so you have to say that that previous place doesn’t count because they weren’t Celts then.
That’s one reason why the standard academic way of identifying “Celts” is to say “people who spoke a Celtic language as their community language.” If the language is not identifiably Celtic, they’re not Celts. For ancient peoples, you pretty much have to rely on personal names, place names, and inscriptional evidence. For that reason, “Olduvai Gorge”-type answers are ridiculous. There clearly was a time not all that far back when Celts did not exist, just as there was a time when the USA did not exist even though its people’s ancestors certainly did.
Archaeologically, once you’ve identified a Celtic people you can describe their material culture, and you can trace that people back further, with the caveat that language and material culture probably track but they might not.
Cunliffe is an archaeologist (and a very good one). He is less concerned with, and less expert in, language issues.
Unfortunately, except for toponyms (especially hydronyms) there is little or no linguistic evidence from Europe’s Far West before, say 1000 BC. Is that correct? When I Google to search for “hydronyms of the British Isles”, papers begin their chronology of hydronyms with Celtic. Are we to believe that the Beaker people—certainly very influential in Britain during the pre-Bronze and Bronze epochs—left no toponyms that can be discerned? Or is it more likely that they already spoke an Indo-European language not dissimilar from Celtic?
Is the following statement correct? The earliest records of “the Celts” show them as a large number of unaffiliated tribes ranging over a huge geographical area. It may be assumed that most of these tribes descended from the Hallstatt culture (or at least its predecessor Urnfield), but those cultures themselves shared attributes, perhaps including language, with other cultures of the West.
Let’s look at some linguistic facts. The split of Italo-Celtic from the rest of PIE can be dated with confidence to about 3500 BC. (This lines up nicely with the Baden and/or Globular Amphora cultures, each often connected with PIE culture.) The almost universally accepted equation of proto-Tocharian with Afanasievo provides good calibration of I-E chronology. (I don’t know if Gray-Atkinson are still pleading, but they admit in private communication that the standard model is probably correct.)
If we equate proto-Celtic with the Urnfield culture, that leaves 2000 years unaccounted for! Where were the speakers of pre-Celtic? Hiding in a cave somewhere? 
And if the Bell Beaker people weren’t speaking pre-Celtic, what were they speaking? There’s a good reason to assume some Indo-European language was spoken in West Central and Western Europe before the Bronze Age: The absence of any strong substrate in the Western languages. From what I’ve gleaned, there’s a small amount of influence from “Berberish”, an even smaller influence from Vasconic (proto-Basque), and an unknown influence unique to Germanic, but other than these no trace of an old non-Indo-European language survives in Western Europe (except of course Basque). (One conjecture is that a now-extinct language sibling to PIE was dominant in Central Europe during the pre-copper Neolithic.)
TL;DR: There is circumstantial reason to infer that many or most of the “Bell Beaker people” spoke a language in the Italo-Celtic family.
It is not correct. There are pre-Celtic hydronyms (e.g. Ness) but not many, and the ones that exist cannot be confidently assigned to a known language. The fact that there seems to be a gap of about twenty or thirty generations between the last non-Celtic speaker and the first documentation of a given place name might be a factor.
No, it is not necessarily correct. That’s the whole point of the debate in this thread.
I disagree with your date for the Italo-Celtic split. It seems about 1500 years too early to me. Already in 700 BC, with the earliest Italic and Celtic inscriptions, they are extremely close. Archaeologists and linguists often have different ideas about when to date language changes, but as a rule I’d go with the linguists, because the archaeologists are often looking to match language groups with physical culture.
Well, I don’t think those 2000 years ARE unaccounted for (see above), but again, if they were, that would just suggest that proto-Celtic speakers weren’t the same as the Urnfield people.
How is the “split of (the earliest) Italo-Celtic from the rest of PIE” dated by evidence regarding the split of Italic and Celtic from late Italo-Celtic?
I’ve sometimes thought of asking on GQ but never got round to it, which are the ‘Pre-Celtic’ river names in Britain? It’s sometimes tossed around as a factoid that British river names are pre-Celtic, but the common ones like Avon and Dee seem to be Celtic.