Yan State was one of the seven main states that existed during ancient China's Spring and Autumn Period (771-476 BCE). It was located in the northeastern part of China and was founded by a man named Ji Yan.
Imagine a big puzzle of China that's made up of many different pieces. One of those pieces is the Yan State - it's kind of like a puzzle piece all on its own. The people who lived in the Yan State had their own government, laws, and culture that were different from the other puzzle pieces around them.
The Yan State lasted for a long time and had many different rulers. Some of them were good and some of them were bad. But despite any problems they faced, the people of Yan State worked hard to build a strong community and to protect themselves from outside threats.
Eventually, the Yan State was conquered and absorbed into another state called the Qin Dynasty. But even though it doesn't exist anymore, it left a lasting impact on Chinese history and culture. And now, when people study China's past, they often talk about the Yan State as an important part of the story.