Short answers, pulled from the story.
The Bacchae premiered posthumously at the Theatre of Dionysus in 405 BC. It was part of a tetralogy that also included Iphigeneia at Aulis and Alcmaeon in Corinth, and it won first prize at the City Dionysia festival.
Euripides wrote The Bacchae during his final years in Macedonia, at the court of Archelaus I of Macedon. He did not live to see the play performed.
The Bacchae follows the god Dionysus, who returns to Thebes disguised as a mortal to punish his royal family for denying his divine origin. He drives the women of Thebes mad, lures King Pentheus to Mount Cithaeron in female disguise, and engineers the king's death at the hands of his own mother, Agave, who tears him apart believing he is a mountain lion.
The Bacchae is regarded as Euripides's masterpiece because of the integration of the chorus into the plot, the god's role as an active protagonist rather than a distant presence, and the play's extraordinary combination of lyric beauty and gruesomeness. Helene P. Foley noted that Dionysus simultaneously functions as the play's author, costume designer, choreographer, and artistic director within the drama.
In his biography of Marcus Licinius Crassus, Plutarch reports that after Crassus was defeated and killed at the Battle of Carrhae in 53 BC, his head was sent to the king of Parthia, Orodes II, where it was used as a prop standing in for the head of Pentheus in a production of The Bacchae.
Major operas based on The Bacchae include Giorgio Federico Ghedini's Le Baccanti, which debuted at La Scala in Milan on the 22nd of February 1948; Harry Partch's Revelation in the Courthouse Park, first performed in 1960; Hans Werner Henze's The Bassarids, composed in 1965 with a libretto by W. H. Auden and Chester Kallman; and John Buller's Bakxai, produced at the English National Opera in London in 1992 with a libretto in ancient Greek.