The
First Peloponnesian War (460–445 BC) was fought 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. This war consisted of a series of conflicts and minor wars, such as the
Second Sacred War. There were several causes for the war including the building of the Athenian long walls, Megara's defection and the envy and concern felt by Sparta at the growth of the Athenian Empire.