Tereus (Ancient Greek: Τηρεύς, Tēreus) is a lost Greek play by the Athenian poet Sophocles. Although fragments have long been known, the discovery of a synopsis among the Oxyrhynchus Papyri has allowed an attempt at a reconstruction. Although the date that the play was first produced is not known, it is known that it was produced before 414 BCE, because the Greek comedic playwright Aristophanes referenced Tereus in his play The Birds, which was first performed in 414. Thomas B. L. Webster dates the play to near but before 431 BCE, based on circumstantial evidence from a comment Thucydides made in 431 about the need to distinguish between Tereus and the King of Thrace, Teres, which Webster believes was made necessary by the popularity of Sophocles's play around this time causing confusion between the two names. Based on references in The Birds it is also known that another Greek playwright, Philocles, had also written a play on the subject of Tereus, and there is evidence both from The Birds and from a scholiast that Sophocles' play came first.
Some scholars believe that Sophocles' Tereus was influenced by Euripides' Medea, and thus must have been produced after 431. However, this is not certain and any influence may well have been in the opposite direction, with Sophocles' play influencing Euripides. Jenny Marsh believes that Euripides' Medea did come before Sophocles' Tereus, based primarily on a statement in Euripides' chorus "I have heard of only one woman, only one of all that have lived, who put her hand on her own children: Ino." Marsh takes this to imply that as of the time of Medea's production, the myth of Tereus had not yet incorporated the infanticide, as it did in Sophocles' play. Akiko Kiso was the first Japanese scholar to publish on Sophocles. In 1984 Kiso published The Lost Sophocles, which reconsidered fragments of Sophocles' lost works. It included reconstructions of Epigoni and Tereus.
