8.20-21

Peloponnesian War...

Struggle between Sparta and Athens, and their allies, that lasted from 431 until the defeat of Athens in 404 BC. Neither side had the means to destroy the other, but Athens was weakened by the losses of the Sicilian expedition (415-413 BC) and Sparta was strengthened by Persian support. Sparta's final naval victory at Aegospotami (405 BC) broke Athens' link with its Black Sea grain supplies and led to its surrender.

Andromeda Encyclopedic Dictionary of World History (2001).