Celtica, homeland of the Celts?

Before the Roman conquest, the British are supposed to be Celts. The whole theory of the language transition in Britain is based upon this 'Celtic fact'. The assumption is that the Celts were a 'people', and the Britons were a part of that people. The Celts were some sort of nation, sharing a single culture and language, albeit divided politically amongst themselves. No proof has ever been given for a 'single people' nor for a common language.

The homeland of the Celts is called Celtica. Some (like Stephen Oppenheimer) believe that Celtica was situated in the south of France, most others believe that it was in south Germany (Bavaria). Eventually, the 'Celtic zone' comprised all of Britain, including Ireland, most of France, Belgium and southern Germany.
There is certainly no genetic link between all those regions. In fact, the opposite is true. The genetic diversity is great. For example, people from the region of Paris didn't like to be called 'Gauls', according to Caesar. They preferred the word 'Celts'. They differ genetically a lot from those other Celts, the Bretons, who live in the most western part of France: Brittany.
There is no proof for a single language [1]. Again: what we know of the ancient local languages indicates the opposite. E.g. the south of Gaul (some will say Celtica ! ) spoke Occitan (Caesar), not what is allegedly called a 'Celtic language'. The Occitan language group is also called the Roman language group (Occitan-Romance), or is a part of it.
What we know is that there was a common Celtic culture. Just like what Europeans have today. A common culture does not imply a single language, not today, not 2000 years ago. Celtic was a fashion, a civilization.

Etymology of the word Celt

 

Etymology dictionaries agree that the word Celt than its origin in Latin and Greek.

In fact "Kelt" is better - the Roman character 'C' is to be pronounced as 'K'.
The modern character 'K' is a recuperation of the ancient Greek character 'K'

No relation with common modern words is given. Is that due to politics? But the similarity with an old proto-Indo-European (PIE) word is quite too obvious. Consider following words: col (fr)/ cult / culture / culminate / helmet / hill and more. Those words are derived from the Indo-European word *Kel meaning “sticking out”, height, superior. *Kel must have existed in a lot of variations, slight differences in pronunciations (*Kwel meant 'turning' - the Latin word 'colere' is derived and means 'farming, turning the soil' - cultura is derived form colere. The earliest meaning is agriculture).
Probably the oldest and broadest meaning of *Kel is: a movement from a ‘flat’ or ‘normal’ situation to a ‘higher’ or ‘more evolved’ situation.

Hallstatt

The origin of the Celtic civilization most probably lies in Austria (the Salzburg region with its salt mines). Its most early occurrence is called the Hallstatt culture. This culture is believed to have emerged in south-east Germany or central Europe. The word Kelt has no relation with the word Gallic or Gaul.

Cultures do not come out of the blue. It is clear that the Celtic culture was influenced by Greek culture. Another probably important participant or precursor is the north of France region. This region had the money to induce superior art. It was (and is) a rich agricultural region where technological research could be financed. It is not a coincidence that the Gothic art emerged in this part of Europe. This was probably the reason why Caius Julius Caesar quoted the 'Gauls' of Northern France saying that "they preferred to be called Celts." According to them, they invented Celtic art. The salt mines in Austria (Hallstatt, Salzburg) provided the region the money to elevate this Celtic art up to its highest and most luxurious level. From there it was re-exported back to the west.

 

German Celts

 

St. Jerome wrote at the end of the 4th century in a comment to "the epistle of St Paul to the Galatians" that the Galatians (Turkey) spoke the same language as the Treveri, which is German (Comentarii in Epistolam ad Galatos, II:3.). Several Roman writers (Caesar, Strabo, Tacitus) mentioned the German origin of the Treveri. For Tacitus' phrase click here .

The story of the Galatians is reasonably well attested. They migrated south through the Balkan, looted a part of Greece (281 BC) and were eventually convinced to settle in West-Anatolia (Central-west Turkey). See: Wikipedia for Galatia (although there too, they are considered to be Gauls)

St. Jerome had visited both regions and knew what he was talking about: St. Jerome or Eusebius Sophronius Hieronymus became famous for his translations of the Bible [2]. The word 'Galatoi' has therefore nothing to do with 'Gauls' but is a synonym of 'Keltoi' (Celts). But even the Romans confused them with Gauls and called them 'Galli'. Gauls were for the Romans the inhabitants of the imperial administrative region between the Pyrenees and the Rhine river. A specific or single language was not implied [3].

A language specialist has for me more credibility than some Romans who were little interested in language, not even their own. Let's not forget that the official Roman language in the eastern part of the Empire always was Greek.
Galatians were Celtic Germans who had migrated to Anatolia (Turkey).

This is the proof that:
(a) Celtic has nothing to do with a specific language like Brythonic (like proto-Welsh). There never was a Celtic people or ethnicity, only a culture.
(b) The culture most probably was finalized in rich southern Germany or Austria, from where it spread (peacefully) to the west. It is however likely that this 'west' (northern France / Belgium) contributed significantly to the culture via cultural exchanges.

The Greek historian Herodotus placed Celtica at the source of the Danube (German Bavaria). This was of course hearsay, but the information is surprisingly precise. He seemingly thought that the source of the Danube was situated north of the Pyrenees. There was however also a Celtic region north of the Pyrenees.

According to Strabo [4], the Romans introduced the name Germani, because the Germanic tribes were the authentic Celts (γνησίους Γαλάτας). Strabo noticed the similarity between the Latin words 'Germanus' (a noun referring to the people) and 'germanus' (an adjective - meaning offspring, descendant, having the same ancestors, therefore : authentic). Although there is no etymological relation, he must have known that the (south) Germans were acknowledged as authentic Celts by the Romans.

At the time Strabo wrote his Geographica, the whole region south of the Danube has been for at least 50 years firmly in Roman hands. Stating that this region was Celtic speaking and that those Celts were later replaced by 'real' northern Germans or that a language change had been imposed, is therefore preposterous. The region was one of the last regions which remained loyal to the crumbling Roman empire.

Dio Cassius (155-225 AD) says that the Suebi (a German tribe deeper in Germany) "dwell across the Rhine (though many cities elsewhere claim their name)" and that they were anciently called Celts: Earlier he had explained [5] "...very anciently both peoples dwelling on ether side of the river were called Celts.". The river is the river Rhine.

All this gives us a clear proof that 'Celts' as a people never existed. They spoke languages as various as High German, continental Brythonic, proto-Flemish (Low German), Insular Brythonic and proto-English.