Who in ancient Rome was called by such nicknames: Thracian, Syrian, Gallus? Why didn’t these people have names?

The inhabitants of the captured Macedonia were called Thracians, the inhabitants of the Syrian kingdom were called Syrians, and the captured Gallic peoples were called Gauls. They were not citizens, so they only had nicknames.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.