The Peloponnesian War ( 431–404 BC ) was an ancient Greek war fought by the Delian League led by Athens against the Peloponnesian League led by Sparta .

The First Peloponnesian War ( 460–445 BC ) was fought Hostile_encounter between Sparta as the leaders of the Peloponnesian League and Sparta 's other allies , most notably Thebes , and the Delian League led by Athens with support from Argos .

Athens further consolidated Cause_change_of_strength their position by making Causation Aegina a member of the Delian League and by ravaging Destroying the Peloponnese .

Megara returned Arriving to the Peloponnesian League and Aegina became Becoming a tribute-paying but autonomous member of the Delian League .