"Decline and Fall of the Roman Myth"

The Celts were more sophisticated than the Romans in some aspects. Celtic culture and history isn't my area, except where it bumps up against the Early MA Germans. What both didn't give us--and what Rome did--was a written record. That, as they say, has made all the difference. Until now.

It has been easy to underestimate Celtic technological achievements because so much has vanished or been misunderstood. Of course, it was thoughtless of the Celts not to leave us anything much in the way of written records — they should have known that the lack of books putting forward their own propaganda would weight the evidence firmly in favour of the Romans.

Western society’s enthusiasm since the renaissance for all things Roman has persuaded us to see much of the past through Roman eyes, even when contrary evidence stares us in the face. Once we turn the picture upside-down and look at history from a non-Roman point of view, things start to look very, very different.

I'd also add that doing away with assumptions of ethnic and cultural homogeneity is also crucial (cf; Patrick Geary's work). All this and more can be found in Terry Jones' (yup, the Python one) new book Barbarians.