I am just trying to narrow things down a bit. We have talked a lot about some of the interdisciplinary studies but not the main idea of the book or books.

Looking over information on the European Bronze Age, I found this:
UPDATE for ‘Megaliths and After’. March 2012 By Guy Gervis


1) Sir Barry Cunliffe proposes that the origin of Indo European languages lies with the Celts, the spread of the language eastwards being due to the wide spread of Celtic trading ventures. This idea was originally put forward in ‘Facing the Ocean’. It was then published in the Proceedings of the Prehistoric Society 2009, under the title ‘A Race Apart: Insularity and Connectivity’ It is also covered in ‘The Celts: a very short introduction’

The issue of a Celtic origin for the Indo-European languages (item 1) has become quite a battleground involving a wide spread of disciplines. The original idea developed from the growth of medium to long distance trade, demonstrated by archaeological finds commencing around 9000 BC and in full flow by 5500 BC , indicating strong connectivity for North Western Europe. Genealogical DNA tests have tended to support the archaeological view that there were no significant east-west movements into Europe after about 9000 BC, but historical language studies are also involved, as are Celtic studies.
When thinking about the possibility of this language spread, it is worth remembering that we are not dealing simply with coastal traffic along Atlantic coasts and through to the Baltic, but also movement along a complex network of rivers which was building up around 5500BC, implying an enormous amount of personal contact, vital for language spread.
It is a big claim and I have no doubt it would be the source of a great deal of grant writing.

Instead of saying that those who moved east were not Celts they are saying that essentially they were all Celts until they developed different languages? Or is there province to subdivide the languages arising from a Celtic root?