The Spartans move north from Chios to the Hellespont, gradually overcoming the Athenian navy despite effective countermeasures taken by Alcibiades and others. (This stage of the Peloponnesian war is called "Decelean" from the name of a town in Attica, Decelea, which Sparta fortifies—to the enormous cost of the Athenians.)

The Athenians decisively defeat the combined Persian-Spartan land and sea forces in 410 at the Battle of Cyzicus.

Sparta requests a peace, with the status quo intact, but the demagogue Cleophon, Athens’ new ruler, refuses.

Alcibiades, still officially exiled but appointed commander of the Athenian navy, helps Athens to a spectacular recovery, defeating the Spartan fleet in the Hellespont at Abydos (411 BCE) and Cyzicus (410 BCE) on the shore of the Propontis (Sea of Marmara) and regaining control over the vital grain route from the Black Sea.

Alcibiades installs a garrison at Chrysopolis under Theramenes, who had commanded twenty ships at Cyzicus, to exact a tithe from all shipping that comes from the Black Sea.

This revenue enables the Athenians to put an end to the regime of the Five Thousand and restore their traditional institutions in full.

A commission is set up to codify the law: it is evidently felt that constitutional history had been abused in 411 BCE and that the abuse had been made possible through ignorance.

Codification is to prevent a recurrence; it is expected to take four months (but will still be incomplete after six years).

A fresh start is to be made in 403 BCE.

In a remarkable reversal of the position in 413 BCE when a Spartan victory must have seemed in sight, Sparta (possibly) at this time requests a peace, with the status quo intact, but the demagogue Cleophon, Athens' new ruler, refuses to come to terms. (Xenophon, who now replaces Thucydides as the main source, does not mention the offer.)

Athenian ally Corcyra quits the war, however, in 410 BCE.

Sicily has always been prone to tyranny and political instability, partly because the island is threatened by potentially hostile neighbors ready to encroach and partly because there is a large population of non-Greek indigenous inhabitants such as the Sicel forces mobilized in mid-century by Ducetius.

Polis life has never struck deep enough roots, and populations tend to be mixed and are too often transplanted.

Immediately after the severe defeat of Athens by the Spartans and their allies at Cyzicus.

a radical democracy had been installed in Syracuse, at the instigation of an extremist called Diocles.

The leader of the moderate democrats, Hermocrates, had in held the position of admiral during the battle.

As a result, Hermocrates, who happens to be absent at the time, is banned "in absentia" in 410.

(Hermocrates, who will not return to Sicily until 408 BCE, will die in a street fight after a failed coup in Syracuse in 407 BCE.

Carthage goes to the help of Segesta, an ally in Sicily, in 409 BCE and turns the war into one of revenge for the earlier defeat of Hamilcar's forces at Himera in 480 BCE.

Hannibal, son of Gisgo, grandson of Hamilcar, and shofet of Carthage in 410 BCE, reasserts Carthaginian power in Sicily by invading the island with an army of one hundred thousand men.

The Carthaginians destroy Selinus; the city's walls are razed, and only twenty-six hundred of its inhabitants escape. (Selinus, although repopulated as a Carthaginian tributary, will never truly recover.)

Hannibal next besieges Himera, where his grandfather had met his death.

The Carthaginian forces enter the city-state in 409, plunder it, and permanently destroy it before departing.

In the process of this conquest Hannibal is said to have killed some three thousand prisoners of war, reportedly as revenge for the defeat his grandfather suffered in the Battle of Himera seventy years before.

It can never have been in much doubt that a combination of Persia and Sparta could win the war easily, even after the particular failures of trust and understanding in 411.

However, Tissaphernes, fearing that a complete victory of Sparta over Athens in the Peloponnesian War will endanger Persian interests, has supplied only limited assistance to his ally.

As a result, when the Persian king Darius II in 407 decides to support Sparta fully, Tissaphernes is replaced as commander in chief in Asia Minor and as satrap of Lydia, Phrygia, and Cappadocia by Darius' son, Cyrus the Younger, and his influence is limited to the satrapy of Caria.

Cyrus, the younger son of Darius and his wife, the cruel and ambitious Parysatis, is the favorite of his mother, who hopes to secure the succession for him instead of her eldest son, Arsaces.

Cyrus and Lysander, the commander of the Peloponnesian fleet in 408-407, get on instantly (it surely helps their relationship that Persia has made concessions, if make them it has, about the autonomy of the Greek cities).

Lysander, as admiral of the Peloponnesian fleet in 408-407 BCE, improves its condition with the assistance of Cyrus the Younger.

Hippodamus of Miletos dies around 408 BCE. (The Greek geographer Strabo will credit Hippodamus with planning the city of Rhodes in 408—07 BCE but most modern authorities doubt that he was still active at this time.)

Rhodian affiliations during the classical period have vacillated between Athens, Sparta, and Persia, in attempts to preserve a balance of power.

The three city-states of Rhodes—Lindos, …

…Ialysos, and …