Answer:
The invasion of the Vikings
Step-by-step explanation:
Vikings from what is today Norway and Denmark got to some parts of Britain in the 8th century.Then a major invasion by "The great Heathen army" ended up in these vikings having control over a big part of northern Britain, until early in the 10th century. The languages were loosely related because of their germanic roots and the peoples lived amongst one another for a while and after it all happened and the norse left some words were borrowed into english.