Sparta was temporarily the main power until overturned by Thebes three decades later.
Athens and its allies were defeated by Sparta in the Peloponnesian War.
Sparta .
Yes, because Sparta and Athens were once allies but then Athens turned on Sparta and Sparta responded with war.
Sparta led the Peloponnesian League . Athens led the Delian League .
Athens won the first Peloponnesian War but Sparta won the second war
Athens and Sparta
The city-state of Athens and its allies were defeated by Sparta in the Peloponnesian War.
Athens versus Sparta .
Athens and Sparta
The conflict between Athens and Sparta , known as the Peloponnesian War , was won by the city-state of Sparta .
. . . the Peloponnesian War .
Athens and its empire versus the Peloponnesian League led by Sparta.