What war did Sparta and other city-states join forces in their building?

Sparta and other Greek city-states joined forces during the Peloponnesian War, which lasted from 431 to 404 BCE. This conflict was primarily fought between the Delian League, led by Athens, and the Peloponnesian League, led by Sparta. The alliance of Sparta and its allies aimed to counter the growing power and influence of Athens. Ultimately, the war resulted in the defeat of Athens and a shift in power among the Greek city-states.