What are the reasons for the emergence of the great powers of antiquity? What role did they play in the development of mankind?

The formation of states was based on various reasons. In areas where natural conditions made it possible to carry out large-scale work, for example, irrigation when growing crops, as in ancient Egypt, the unification of many people was required, this could only be with a general leadership. The formation of various classes, as in ancient Greece, the poor and the rich, required the presence of an army to contain those dissatisfied with uprisings, control the slave owners over their slaves, and wage war. In the early states, writing, counting, laws, and household items were first invented.