Peace (Greek: Εἰρήνη) is a comedy by Aristophanes, first performed at the Great Dionysia in 421 BC, where it won second prize. It satirises the contemporary political situation following the battle of Amphipolis, when the deaths of the Athenian general Cleon, and the Spartan Brasidas, paved the way for the Peace of Nicias, an outcome which Aristophanes enthusiastically anticipates.
Free online texts
Gutenberg: Peace. English translation, multiple formats.
Internet Archive: L 488 - Aristophanes II - Peace, Birds, Frogs. Bilingual Greek-English Loeb edition. Multiple formats.
Poetry in Translation: Peace, translated by George Theodoridis. Multiple formats.
University of Adelaide (Internet Archive): Peace. English translation, HTML format.
History of Ancient Greece: o54- Old Comedy and Aristophanes. Podcast by Ryan Stitt.
Wikipedia: Peace (play)
The Great Conversation: Further reading at Tom's Learning Notes
Thucydides - Our best source for the political events which provided the occasion for Aristophanes' satire, although one which took a similarly jaundiced view of Cleon's career.
Ancient Greek resources: Learn to read Greek classics in the original.