Check out the full story as told by our homeboy Thomas Bulfinch:
Bacchus was the son of Jupiter and Semele. Juno, to gratify her resentment against Semele, contrived a plan for her destruction. Assuming the form of Beroe, her aged nurse, she insinuated doubts whether it was indeed Jove himself who came as a lover. Heaving a sigh, she said, "I hope it will turn out so, but I can't help being afraid. People are not always what they pretend to be. If he is indeed Jove, make him give some proof of it. Ask him to come arrayed in all his splendours, such as he wears in heaven. That will put the matter beyond a doubt." Semele was persuaded to try the experiment. She asks a favour, without naming what it is. Jove gives his promise, and confirms it with the irrevocable oath, attesting the river Styx, terrible to the gods themselves. Then she made known her request. The god would have stopped her as she spake, but she was too quick for him. The words escaped, and he could neither unsay his promise nor her request. In deep distress, he left her and returned to the upper regions. There he clothed himself in his splendours, not putting on all his terrors, as when he overthrew the giants, but what is known among the gods as his lesser panoply. Arrayed in this, he entered the chamber of Semele. Her mortal frame could not endure the splendours of the immortal radiance. She was consumed to ashes.
Jove took the infant Bacchus and gave him in charge to the Nysaean nymphs, who nourished his infancy and childhood, and for their care were rewarded by Jupiter by being placed, as the Hyades, among the stars. When Bacchus grew up he discovered the culture of the vine and the mode of extracting its precious juice; but Juno struck him with madness, and drove him forth a wanderer through various parts of the earth. In Phrygia the goddess Rhea cured him and taught him her religious rites, and he set out on a progress through Asia, teaching the people the cultivation of the vine. The most famous part of his wanderings is his expedition to India, which is said to have lasted several years. Returning in triumph, he undertook to introduce his worship into Greece, but was opposed by some princes, who dreaded its introduction on account of the disorder and madness it brought with it.