African-American heritage of presidents of the United States
Calvin Coolidge's mother Victoria Moor was claimed to be of a mixed-race family in Vermont. Vaughn noted that her surname was derived from "Moor", a European term for people of North Africa. He did not note that another meaning of her surname is the landscape feature of moor or bog. People's surnames were often based on such landscape features when surnames became generally adopted in 14th century England. Moor/Moore is a common name in England, Scotland, and Ireland.
History of Spain
The most visible effect was the depopulation of the cities as they moved to the countryside. Even while the country enjoyed a degree of prosperity when compared to the famines of France and Germany in this period, the Visigoths felt little reason to contribute to the welfare, permanency, and infrastructure of their people and state. This contributed to their downfall, as they could not count on the loyalty of their subjects when the Moors arrived in the 8th century.