By 11th century the Normans became the rulers of England for many years. Hence, indeed, there is a Norman element in Britain. After the Normans stopped ruling England no other ethnic groups made significant inroads to Britain (Trevelyan).
are spread over many countries in all the continents now. This is indeed a colonial legacy. Another colonial legacy is the influx of races from former colonies to Britain. While the Britons were in the colonies they were the ruling class and the Africans, Asians and the Caribbeans their subjects. However after the dismantling of the colonial empire, back in the country of their former masters, they became citizens. Citizenship meant a perception of legitimate right for equal rights with the fellow whites. This is the background to the tensions between the ethnic minorities in UK and the whites.
The attitude expressed in the ditty, is not typical to the Anglo-Saxons, it was somewhat universal. The Jews generally believed that their special relation with Jehovah made them the superior. However they did not try to establish their biological superiority. But the Victorian Anglo-Saxons believed that they are racially superior, and qualities like literary taste, creativity and even honesty
were inherited by them by virtue of bei ...