So you know how some people have servants who work in their houses and do chores for them? Well, a long time ago in the British Isles, some people had servants who were enslaved. This means that they were treated really badly and were not allowed to leave or make any choices for themselves.
The people who were enslaved in the British Isles were usually brought there from other countries, like Africa, through a really horrible trade called the slave trade. The slave traders would capture people and force them onto big ships to take them to the British Isles to be sold.
Once the enslaved people were bought by someone, they were forced to work for them without getting paid or having any rights. They would do all sorts of hard work, like working on farms or in people's houses. Sometimes they were even treated like objects instead of like human beings.
Eventually, people started to realize that slavery was really wrong and unfair. They fought to have it abolished, which means to make it illegal. It took a long time and a lot of fighting, but eventually, slavery was made illegal in the British Isles in the 1800s.
Today, we know that slavery is one of the worst things that can happen to a person. It's important to always remember the horrible things that happened in the past, so that we can make sure they never happen again in the future.