Imagine you and your friends are playing a game and you need someone to be in charge to make sure everyone is playing fairly. That's kind of what a government does - it's in charge of making sure everyone is playing by the rules and things are running smoothly.
Now, let's talk about Western Thrace, which is a place where people live. A long time ago, the people who lived there were ruled by the Ottoman Empire, which was a big group of people who controlled a lot of different places. But then, something called World War I happened and the Ottoman Empire was broken up into smaller parts.
After the war was over, some people from Greece wanted to take over Western Thrace and make it part of their country. But the people who lived in Western Thrace didn't necessarily want to be part of Greece - they had their own culture and language and wanted to be able to keep that.
So, a group of people from Western Thrace got together and created what's called a provisional government. "Provisional" means it's temporary - like a placeholder until something more permanent can be worked out. The purpose of this provisional government was to have a group of people who could speak for the people of Western Thrace, negotiate with other countries, and help figure out what the next steps should be.
It wasn't easy, and there were a lot of disagreements between the people who wanted Western Thrace to be part of Greece and the people who wanted it to be its own thing. But the provisional government was able to keep things relatively peaceful while they worked things out.
Eventually, after a lot of negotiations, Western Thrace was officially made part of Greece. But the existence of the provisional government shows that sometimes, people need to come together and make their voices heard when big things are happening around them.