CEVAP:

One of the main reasons that ended the development of city-states was the conflicts between them. Wars broke out between many city-states. An example of this happened in Athens and Sparta. Moreover, religious differences brought about a lack of homogeneity, and also the changes in class and caste weakened many of the city-states. This, combined with the growing power of states surrounding the city-state, led to the end of citystates eventually.