Long long ago, in a faraway land called Europe, there were people who were called Celts. They were very brave and adventurous people. They used to live in different parts of Europe, but many of them came to live in the southeast part of Europe.
Now, imagine a big map of Europe, and we are going to look at a smaller part of it which is in the southeast. This place is called the Balkan Peninsula. The Celts liked to live in this area because it had many mountains, forests, and rivers. They loved to explore and hunt in these places.
When the Celts came to the Balkan Peninsula, they brought their own language, their own beliefs, and their own ways of doing things. They built their own houses, made their own tools, and grew their own food like wheat and corn.
But, the people who already lived in this area were not too happy about the Celts coming and taking over their land. They had their own language and their own way of doing things. They were called Illyrians and Thracians.
Despite all the differences, the Celts and Illyrians and Thracians still found a way to live together. They traded with each other and even fought together against other enemies. They learned from each other's cultures and made a beautiful and diverse place to live.
And that, my dear child, is how the Celts settled in the southeast part of Europe, and how they lived among other different people who also loved their land and their culture.