The Brothers Menaechmus is a comedy of mistaken identity, written by the Roman playwright Plautus around the beginning of the second century BC. With its shimmering wordplay, twisting plot and virtuosic use of metre, the play served a crucial role in the development of comedy as a genre, inspiring playwrights such as Shakespeare and Molière. It is among the earliest Latin works to have survived intact.

Moschus, a merchant from Syracuse, in Sicily, has twin sons, Menaechmus and Sosicles. He takes Menaechmus with him to sell goods at Tarentum, where the boy is kidnapped by a rich, childless merchant from Epidamnus in Greece. Moschus dies from a broken heart and Sosicles is renamed Menaechmus (written, for the purposes of the play, as Menaechmus II), in remembrance of his lost twin. Meanwhile, the original Menaechmus inherits great wealth in Epidamnus and is married off to a rich woman.

The play takes place in Epidamnus. Menaechmus has stolen a dress from his wife as a gift for his lover, a prostitute named Erotium, and is planning a great banquet with her and his parasite, or hanger-on, Peniculus. While Erotium’s cook prepares the feast, Menaechmus and Peniculus go off to the forum. At this point, Menaechmus’s brother arrives in Epidamnus with his slave, Messenio, having travelled for six long years in search of his twin. With the brothers looking completely identical, right down to their costumes, chaos and confusion unfold.

Menaechmus II is invited into the feast by Erotium and her cook. Although at first he is taken aback, having no idea who Erotium is and having been warned by Messenio of the dissolution and decadence of Epidamnus, he eventually goes inside the house, leaving Messenio in charge of their money. Hurrying back from the forum, Peniculus mistakes the drunken and well-fed Menaechmus II for his twin and is furious at being excluded from the feast. Erotium gives Menaechmus II the stolen dress, asking him to get it altered, which Menaechmus II promptly steals for himself–his fortunes are on the rise.

The original Menaechmus, however, suffers a drastic reversal of fortune. He is chided by his wife and Peniculus, who order him to retrieve the dress. When he approaches Erotium, she accuses him of trying to swindle her, since she thinks he has in fact already taken the dress from her.

Menaechmus II has a run-in with Menaechmus’s wife, who summons her father to defend her and get her supposed husband to behave. Menaechmus II pretends to be mad to get rid of them, banking on the fact that they already think he is losing his sanity, since he is failing so resoundingly to acknowledge he even knows who they are. The wife’s father hurries to fetch the doctor, hoping to find out what is wrong with his son-in-law.

When he returns with the doctor, however, they end up examining Menaechmus himself, who has no idea what is going on. His exasperation is interpreted by the doctor and father as signs of his madness, and they rush off to get slaves, in order to apprehend him. As the slaves try to take him away, Menaechmus is rescued by Messenio, who thinks he is his master. The grateful but bewildered Menaechmus agrees to free Messenio from slavery in return.

Messenio then bumps into Menaechmus II, who denies that he has freed him and continues to treat him as his slave. Just as the knot of confusion seems intractable, Menaechmus himself enters the stage. It is Messenio who notices the resemblance and who realizes what has been happening. The twins are reunited at last, and the confusion is laid to rest. Messenio is granted his freedom, while Menaechmus decides to sell his property and return to Syracuse with his brother.