If one goes back in history, one can see that initially the primitive people, then the Celtic tribes lived in Britain before the Romans came. After the Romans had withdrawn after 400 years, there were people from Northern Germany already in Britain and then there was a migration by Jutes, Angles, Saxons, Frisians from Europe to Britain and the original population moved to the western part, like Wales and Cornwall. Later the Vikings came during the eighth century.
Words that still exist in the English language today can be traced back to the migrants. In 1066 the Battle of Hastings and the victory of the Norman William the Conqueror ended the rule of the Anglo-Saxons. It had a great influence on the way of life of the indigenous population.