> Do you agree with Harper that there is something
> "anomolous" about the effect ascribed by historians to the
> Anglo-Saxon invasion? Do you agree that this anomoly has not
> received due attention?
The anomaly of British linguistic history (supposed, if you will)
Around 500 AD, the languages of the British isles were mainly Celtic as far as I understand it. The Celts of Britain didn't seem to adopt the language of the Romans the way the Celts in their Iberian homeland (Ireland comes from Iberia + land) did. So while the Celts of Spain, Portugal and France intermarried with the Romans and adopted their language, the Celts of Britain were more... insular.
Around 500 AD, they were having problems with the Picts to the north who may have been descended from a Uralic tribe. The Celtic king of Britain, Wor-Tigern or however you spell it, supposedly invited a group of Angles, Jutes and Saxons led by two brothers, Hengis and Horsa, to come to the isles and help them fight the Picts. They apparently helped to completely wipe out the Picts.
Now, allies will usually borrow vocabulary from one another, enemies don't. This is why we have no real idea what languages the language of the Picts may have been related to because the Picts were all wiped out and neither the Celts nor the Germans borrowed any words from them.
The anomaly is that neither the Germans nor the Celts borrowed words from each other at this time, so it would appear more likely, on linguistic evidence, that they Celts and the invading Germans were not really on good terms. They didn't intermarry the same way the Celts and Romans did, and they didn't exchange vocabulary with one another.
On the other hand, the Jutes, Angles and Saxons did intermarry, and there were intermarriages and business dealings between these peoples and the Viking descended Northumbrians. All these people spoke Germanic languages but with different case and gender endings. This created a slight linguistic barrier to communication that was resolved by everyone eventually dropping all of their case and gender endings and relying more on word order for syntax.
With the Norman invasion of 1066, the Germanic population continued speaking their Germanic dialects but there was extensive borrowing from the Late Latin of the Norman royalty into what became Middle English.
Anyway, that's how I understand the conventional view of British linguistic history. The primary anomaly that I'm aware of is the lack of borrowing between the Celtic languages and the invading Germanic tribes. It appears more likely that it was an invasion on the part of the Germans and that the story about helping to defend the Celts from the Picts was just that, a story, propaganda.