The truce with Sparta expires in April…

Cleon decrees after suppressing the rebellion in Scione that all the male citizens be put to death and the women and children enslaved.

The Athenian democracy votes its assent.

Surprised by Brasidas' troops at Amphipolis, Cleon is defeated and killed in 422; Brasidas, although victorious, also dies in the battle, thereby removing the key members of the pro-war faction of both sides.

Megarian Greeks from Heraclea Pontica in 421 BCE reestablish the city of Chersonesus in the southwestern Crimea on the southern shore of the long, narrow Akhtiarskaya Bay, which forms a magnificent natural harbor; it becomes a Dorian city.

The deaths of Cleon and Brasidas, together with the imminent expiration of the Argive peace, as well as the Athenian occupation of Cythera, which provides a base for deserting helots, …

…lead in 421 BCE to the misguided Peace of Nicias and an alliance with the Spartans, ending the war (called, in this stage, Archidamian, from Archidamus, the Spartan king), in stalemate.

The essence of the Peace of Nicias is a return to the prewar situation: most wartime gains are to be returned.

Sparta has resoundingly failed to destroy the Athenian empire, and in this sense Athens, whatever its financial and human losses, has won the war.

Aristophanes in The Wasps, produced in 422 BCE, had ridiculed the mania for litigation and paid jury service displayed by the senior citizens of Athens.

Euripides in the same year had written another patriotic play, The Suppliant Women.

Aristophanes celebrates the recent armistice with Sparta in The Peace, produced in 421 BCE.

Construction begins in this year on the Erechtheum, where the Ionic order, near its apogee, is displayed to great advantage.

Athens is to retain the Messenian harbor of Pylos; …

…Sparta is to retain Amphipolis.

Corinth and …

…Boeotia, however, reject the peace from the outset.

The Tholos at Delphi constructed around 420 BCE marks the first emergence of a round temple form.

The newly designed Corinthian capitals make their initial appearance on temple exteriors around the same time.