Why does modern England have many different ethnic

groups?

Answer: England has almost always consisted of multiple ethnic groups.

Explanation: The English Empire at its height was the largest in the world. A common phrase uttered at the time of the empire was that "the sun never set on the British empire" meaning that the British had so much land that the sun never fully set on the entire British empire. They're holdings in India, Canada, formerly United States, Australia, South Africa, the Middle East, and parts of Northern Africa brought a mixture of cultures to England itself. These cultures are still a large part of English society as a whole to this day.