Somewhere around 450 AD (according to the Venerable Bede), the Celtic warlord Vortigern, embattled by the northern Picts, made a decision that would change the world: He invited the Frisian brothers Horsa and Hengest to bring their warriors across the sea as mercenaries and help him defeat the Picts. After the fierce northern Germanic warriors ensured Vortigern’s victory, he tried to cheat them out of their payment, and they responded by founding a kingdom in southern England. Thus began the Anglo-Saxon migration, and soon, conquest.
The world went crazy after the fall of Rome. Read the rest. It's about the Olde.Anglosphere. As far as I know, basic English is still Frisian (except for the added Viking, Frenchy, Greek and Latinate stuff).