2 465 BC: Athenians aid rebellious Spartan helots 465 BC: helot revolt broke out in Sparta. Athens (then an ally) sent 4,000 hoplites). The Spartans rejected Athenian help (due to suspicion about Athenian motives). The Athenians settled rebellious helots them at Naupactus on the Corinthian Gulf.
3 459 BC: Athens allies with Megara (against Corinth) and therefore gains control of a highly strategic position on the Isthmus of Corinth. This sets off 15 years of intermittent conflict with Sparta and her allies.
4 445 BC: Peace treaty known as the Thirty Years' Peace – Megara-Athens alliance broken. Agreement to observe respective spheres of influence.
5 440 BC: Athenian ally Samos rebelled with support of Persians 440 BC: Athenian ally Samos rebelled with support of Persians. Spartan alliance decided not to support Samos/ the Persians. Athenians crush revolt.
6 435: Corinth (Spartan ally) defeated by its colony, Corcyra 435: Corinth (Spartan ally) defeated by its colony, Corcyra. Builds naval force to seek revenge. Corcyra allies with Athens.
7 432: PotidaeaPotidaea > originally a Corinthian colony but now a tributary ally of AthensCorinth encourages Potidaea to rebel against Athenian control.Athens quells revolt. Insists Potidaea tears down its defensive walls and expels Corinthian magistrates.
8 432 BC: The Megarian Decree. Megara has, since the Thirty Years Peace, been back in the Spartan sphere of influence. Athenians imposed trade sanctions on Megara. Citizens. Megarians excluded from Athenian ports and markets.
9 Phases of the War1) The Archidamian War, Sparta invaded Attica, Athens raided coast of the Peloponnese > 421 Peace of Nicias 2) Renewed fighting in the Peloponnese > 415 BC, Athens dispatched a massive expeditionary force to attack Syracuse in Sicily; the attack failed disastrously, with the destruction of the entire force, in 413 BC. 3) The Decelean War, or the Ionian War. Sparta, receives support from Persia, supported rebellions in Athens' subject states in the Aegean Sea and Ionia, undermining Athens' empire, and, eventually, depriving the city of naval supremacy. The destruction of Athens' fleet at Aegospotami effectively ended the war, and Athens surrendered in the following year.
10 Results of the War> Sparta becomes dominant Greek city-state, Athens now subject to it > Athenian prosperity destroyed (as well as that of much of the Peloponnese due to the destruction of war) > Total war replaces a more limited and civilized warfare