Semele the daughter of Cadmus, a mortal bride of Zeus, was persuaded by Hera to pray the God to promise her with an oath to grant her whatsoever she would. And, when he had consented, she asked that he would appear to her in all the splendour of his godhead, even as he visited Hera. Then Zeus, not of his will, but constrained by his oath, appeared to her amidst intolerable light and flashings of heaven’s lightning, whereby her mortal body was consumed. But the God snatched her unborn babe from the flames, and hid him in a cleft of his thigh, till the days were accomplished wherein he should be born. And so the child Dionysus sprang from the thigh of Zeus, and was hidden from the jealous malice of Hera till he was grown. Then did he set forth in victorious march through all the earth, bestowing upon men the gift of the vine, and planting his worship everywhere. But the sisters of Semele scoffed at the story of the heavenly bridegroom, and mocked at the worship of Dionysus. And when Cadmus was now old, Pentheus his grandson reigned in his stead, and he too defied the Wine-giver, saying that he was no god, and that none in Thebes should ever worship him.
And herein is told how Dionysus came in human guise to Thebes, and filled her women with the Bacchanal possession, and how Pentheus, essaying to withstand him, was punished by strange and awful doom.