The harrying of the north is a very bad thing that happened a long time ago in England. It was when a cruel king named William the Conqueror got mad at some people in the north part of England for not obeying him. He was so angry that he sent his solders to burn down their houses and take their things. He wanted to make them very poor so they couldn't fight back.
The people who lived there were very scared and had to run away to hide in the woods or in other places where the soldiers couldn't find them. They were very hungry and cold because they did not have any food, homes or warm clothes. It was a very sad time for those people.
The harrying of the north happened for a long time, and many people who lived there died or were hurt. It's not a good thing to do because everyone should be treated with kindness and respect.