Peace (Greek: Εἰρήνη / Eirēnē) is an Athenian Old Comedy written and produced by the Greek playwright Aristophanes. It was staged in 421 BC and was awarded second prize at the City Dionysia festival. As in many of his plays, Aristophanes attacks and lampoons his contemporaries, including Euripides, Carcinus, and Cleon. The jubilant spirit of celebration, contrasting strongly with the sceptical tone of Aristophanes' other 'peace' plays (Lysistrata and The Acharnians), can be attributed to the fact it was written shortly before the Peace of Nicias was sworn.
When Trygaeus eventually arrives at the halls of Zeus, he learns that all the Olympian gods except Hermes have left heaven in the hands of War and his servant Havoc, and that Peace (Eirene) is imprisoned in a deep pit covered in heavy stones. War and Havoc, meanwhile, are in the middle of plotting destruction for the Greeks, using a giant mortar and ingredients that represent the various city states. Fortunately, a pestle is nowhere to be found, and War is forced to search for one, first in Athens and then in Sparta. Neither city has a pestle to lend; the allusion is to the recent death of the Athenian politician Cleon and the Spartan officer Brasidas, which created a historical window in which a peace could be concluded between the two sides.
Seizing this opportunity, Trygaeus summons farmers from various Greek city-states to help him rescue Peace. These farmers make up the play's chorus, and with their assistance Trygaeus removes the stones and rescues. His efforts, he claims, are initially blocked by those whose careers profit from war, such as weapons-makers. But after a great deal of effort, Peace is released, and is accompanied by her companions Harvest and Festival. Peace is still upset over how the Greeks have treated her (such as the many denials of treaties during the Peloponnesian War), and will only talk to Trygaeus and the other Greeks through Hermes. Eventually, she is persuaded to return to Athens.
Trygaeus agrees to marry Harvest (Opora), and Festival is sent with another Greek to prepare a peace celebration. A sheep is chosen for the sacrifice, however no blood is allowed on the altar, as "blood cannot please Peace". An oracle-monger named Hierocles drops by uninvited and wishes to help himself to the meat. But after he begins to prophesize against Peace, he is beaten and forcibly removed.
Arms merchants then enter the town attempting to sell their wares for whatever small sum they can get; since the war is over their wares are no longer needed. Trygaeus adds insult to injury, saying such things as he'll buy a breast plate and use it as a stool, or buy spears to use as vine-props. Insulted, they leave Athens in time for the wedding of Trygaeus and Harvest.