When different groups of people lived in the same area a long time ago, they sometimes fought over who got to live there and who would be in charge. One of those times happened in a place called Galatia, which is now part of modern-day Turkey. The people who lived there were called Galatians, and they were trying to keep their land safe.
Another group of people, called the Seleucids, wanted to take over the land and make it part of their bigger kingdom. They sent armies to Galatia to try and take control of everything.
The Galatians didn't want to give up their land and they fought the Seleucids very hard. The war went on for a few years, but in the end, the Galatians were able to push the Seleucids out of their territory and stay in charge.
This was a big deal because the Galatians were able to keep their own customs and traditions, instead of having to follow the rules of the Seleucids. It also helped them feel safe in their own land, which is something that everyone wants.