How I Wrote Elastic Man wrote:
I wonder what the natives thought when the English turned up?
If you are talking about the Norman Conquest most historians agree that an estimated 8000 Normans and other continentals settled in England as a result of the conquest. The UK population at that time was about 2.5 million.
England has never been a country with large scale immigration until the 1950s.
The only notable exception is from 1670 to 1710, between 40,000 and 50,000 Huguenots from all walks of life sought refuge in England amongst fellow Protestants.