The god tells the audience about how he was struck from his mother, Semele, by a lightning bolt.
He points out the remains of her house which still smolder and flicker with magic fire.
This was all a trick of Hera's, who was jealous that her husband Zeus was having an affair with Semele.
Dionysus praises his grandfather, Cadmus, who made a monument of the place his mother died.
The god talks of how he's conquered places all over Asia, but Thebes is the first city in Greece where he's spread his wild rituals.
He says that he's mad at the sisters of his mother, Semele. They spread a rumor around that he isn't really the son of Zeus, that his mother just slept around and after her death Cadmus made up the story.
To pay Semele's sisters back for their insolence, Dionysus has incited them all to a frenzy. Currently, they're all dancing about in the mountains, and soon Dionysus will cause all the other women in Thebes to join them.
Dionysus says that he's mad at Pentheus, the King of Thebes, who doesn't pay tribute to him as a god. The god tells the audience that he's going to teach the King and all of Thebes a lesson. If Thebes tries to resist, Dionysus will lead his followers in battle.
Dionysus calls on the Chorus, female followers he's brought from Asia, to dance and sing around the city.
The god goes off to the mountains to dance with the women of Thebes, now called the Maenads.