In another battle against the Saxons, Arthur, with bright Excalibur drawn, rushed headfirst into the throng crying the name of God with each killing blow. 470 men he killed that day.
However, the Norman Conquest did not affect English as much as the Angles and the Saxons' vitory about 600 years earlier, which led to Old English replacing Celtic.
Now the Angles, the Saxons, the Jutes, the Vikings. When they invaded, they lived among the people and they were the rulers, but they intermarried with local people.
The area that the Anglo-Saxons conquered like Westeros was divided into small petty kingdoms that eventually coalesced into wouldn't you know its seven kingdoms.
Because all the Saxons who have heard of Uther's death have poured into northern Britain, Arthur lays siege to the city of York in retaliation, and he goes up against the saxons in a bunch of battles.