Who was the winner in Peloponnesian War?

Answer 1

The Spartan-led alliance defeated the Athenian alliance.

However no one won - the Greek cities continued on sporadic fighting amongst each other, Persia imposed the King's Peace on the cities to stop the warfare spilling over into it's empire, and retook control of the Greek cities in Asia Minor it had lost after the Persian War, and all this paved the way for Macedonia to establish hegemony over the Greek cities of mainland Greece which were too weakened and divided by their warring to resist effectively.

Answer 2

The Spartan alliance now called the Peloponnesian League.

Answer 3

Notably , the war was between Athens and Sparta with the Athenians losing the struggle to the Spartans .

Answer 4

. . . the city-state of Sparta .