The Bacchae.

The young wine god Dionysus returns to his native town of Thebes after having established his cult in the east. In his entourage, he has a run of Bacchantes. Semele, his mother, was distrusted by her family when she claimed that Zeus was the father of her child. Dionysus has come to restore her, revealing his divinity, and require proper worship of the Theban legion.