Book IV of Thucydides’s History of the Peloponnesian War opens with yet another revolt from allies of the Athenians, this time in the city of Messana. Syracuse encourages the revolt to prevent Athens from a clear path to Sicily. Additionally, Athens is again invaded by the Spartans under King Agis, son of Archidamus.

Meanwhile an Athenian fleet builds a fort as an outpost in the Peloponnesus (Pylos), under Demosthenes. This sends Athenian forces back to Spartan territory. Demosthenes rallies his troops in defense of their outpost, ironically Athenians defend their occupied Spartan land while the Spartans attack from the sea. It is a reversal of expertise: Athens as infantrymen and Sparta as naval power. Thucydides makes note of this irony.

The Spartans initiate an armistice, initially framed as a “treaty…to end the war, and offer peace and alliance” (4.19). However, the Athenians are swayed by the demagogue Cleon a powerful speaker who is popular among the multitude. However, the lapse of peace is later lamented. As the war drags on, Cleon is blamed for not accepting the Spartan treaty, but he blames the general Nicias who promptly resigns. Thus Cleon leads an Athenian force with Demosthenes to attack the Spartans. After much fighting, the Spartans take heavy losses and surrender, with Cleon returning to Athens emboldened by his victory.

Brasidas successfully encourages revolt in several Athenian provinces, and Pagondus encourages attacks on Athens. Gains and losses are made by both the Spartans and Athenians. The Athenians retreat from battle with the Boetians who commit a great sacrilege by not returning their dead to their native land. Thucydides notes his personal part in the story at (4.104) in the battle for Amphipolis, an Athenian colony, which eventually falls to the Spartans and causes great dismay for the Athenians due to its strategic importance as a critical timber resource.

In the Spring of 423 BC the Athenians secure a truce, a one year armistice, in order to prevent the loss of any more cities to revolts. Thus concludes Book IV.

For this reading I used the impeccable Landmark edition of Thucydides’s History of the Peloponnesian War by businessman-turned classical scholar Robert B. Strassler.