Jupiter made himself king of the gods by kicking out his father, Saturn.
A little while later, his power was challenged by the Giants, but he kicked their butts.
Then a few Ages of humanity pass by. After going down to earth to investigate, Jupiter decides that humans are sleaze-bags.
He collaborates with his brother, Neptune, to whip up a huge storm that drowns all humans – except for Deucalion and Pyrrha. Jupiter spares these two when he sees them cowering on a mountaintop.
Some time later, Jupiter developed a crush on a mortal woman named Io.
He tried to convince her to sleep with him in the woods, but she kept on walking. In response, he veiled the land with a cloud of mist…and then raped her.
Up in the heavens, Juno, queen of the gods, and Jupiter's wife, noticed that a large tract of land down on the ground was covered with clouds. She suspected that her husband is up to no good.
But Jupiter saw her coming. Just before Juno dispersed the clouds, Jupiter turned Io into a white heifer (female cow).
After making some chit-chat about what a nice cow Jupiter had, Juno asked to keep it as a pet.
In his mind, Jupiter went back and forth over whether he should do it or not, but eventually he decided to give her over. He was worried that, if he made too big a fuss about it, Juno would realize that Io wasn't really a cow.
In the end, he decided to give Io up.
Juno tormented Io and entrusted her to a crazy giant named Argus.
One day, Jupiter decided that enough was enough, so he sent Mercury down to kill Argus. Mercury did as he was told.
When Juno saw what happened to her henchman, she sent one the Furies down to torment Io.
The Fury chased Io all over the place, until she eventually came to the Nile. There, Io lifted up her snout to the heavens and mooed for help.
Jupiter heard her and begged Juno to relent, telling her that he wouldn't have anything more to do with Io. (Note that he didn't say he wouldn't ever cheat again with women other than Io.)
Juno accepted and let Io change back into a human.
When we next meet Jupiter, in Book 2, he is called upon to stop Phaethon from burning up the earth. Jupiter obliges by striking him with a lightning bolt.
Then Jupiter wanders around, trying to assess the damage from the fire. On his wanderings, he spies the nymph Callisto, the goddess Diana's favorite handmaiden. He immediately develops a crush on her.
He watches as she goes into the shade of a nearby forest.
Then, he approaches her in the shape of Diana, her mistress. In this disguise, he greets her, kisses her…and then rapes her. Callisto tries to resist, but isn't strong enough.
Jupiter then goes back to the heavens, while Callisto tries to pretend like nothing happened.
Unfortunately, nine months later, when Diana and her other nymphs are about to go bathing, someone rips off Callisto's clothes and everyone can see she's pregnant. Because only virgins could hang out with Diana, Callisto becomes an outcast.
Soon afterward, Callisto gives birth to a son, Arcas.
After this, Juno reveals that it was she who had brought to pass Callisto's pregnancy and motherhood, as punishment for sleeping with her husband, Jupiter.
But that isn't all. As a final punishment for attracting her husband's eye, Juno turns Callisto into a bear.
Sixteen years later, Callisto's son, Arcas is out hunting.
He comes upon his mother, the bear. She vaguely recognizes him, and signals him to come closer. He obviously doesn't recognize her because, you know, she's a bear.
Before Arcas can kill her with his spear, however, Jupiter intervenes. He scoops both of them up and puts them in the sky – turning them into the constellations the Big and Little Bear, or, as we sometimes call them, the Big and Little Dipper.
Jupiter's next erotic adventure centers around a princess named Europa. One day, while Europa is walking along the beach, Jupiter approaches her in the shape of a bull.
He acts friendly and nuzzles her hand. Eventually, his gentleness makes Europa trust in him so much that she sits on his back.
That's just what he's been waiting for – now Jupiter races out into the open sea, carrying Europa away with him on his shoulders.
When he arrives at Crete, still carrying the princess Europa, he abandons his bull shape and turns back into himself.
Time passes. Now Jupiter is fooling around with another mortal lady, named Semele – and Juno knows about it.
Juno considers punishing her husband for this, but decides to take out her wrath on Semele instead.
She goes down to Thebes, disguising herself in the shape of Semele's nurse, Beroe. In this shape, she asks Semele how she really knows that it was Jupiter who got her pregnant. She says that, when Jupiter sleeps with Juno, he appears in all his divine glory. She convinces Semele to demand equal treatment.
Poor Semele. The next time Jupiter visits him, she asks him to grant her a gift. He swears a solemn oath by the River Styx that he will grant whatever she wishes. She repeats what Juno told her – that he make love to her the way he would the queen of the gods. Jupiter doesn't want to comply, but he is bound by his oath – he does as he's told, and Semele is incinerated.
Ovid tells us that her unborn child is later extracted from her womb and implanted in Jupiter's thigh. When the time rolls around, that's where it's born from. This child ends up being Bacchus, the god of wine. Weird.
At some point in time, Jupiter and Mercury go down to earth to see what the mortals are up to.
They wander around a town in Phrygia, knocking on every door. Everyone rejects them except for a poor, elderly couple: Baucis and her husband, Philemon.
Baucis and Philemon give the gods a generous welcome, despite their poverty. In the middle of their supper, they notice that their wine bowl is miraculously replenishing itself. Fearing the wrath of the gods, they pray to be forgiven for their meager offerings.
All of this leaves Jupiter and Mercury deeply impressed. At the end of the supper, they reveal their true identities. Then they tell Baucis and Philemon to follow them. Together they walk up to a hill outside of town. When they reach the top, Baucis and Philemon look back – and see that their entire town has been turned into a swamp. The only house saved is their own.
But then this house turns into a marble temple.
Now Jupiter asks Philemon what he wants most. Philemon confers with Baucis. Then, he speaks for both of them, telling the god that he and his wife want to be their priests. Also, they want to be together for the rest of their lives; when one of them dies, they want the other to die also.
Jupiter and Mercury grant this request. Baucis and Philemon live out the rest of their days as priests in the temple. Then, one day, they both turn into trees – the oak and the linden Lelex sees in Phrygia.
Some time afterwards, Jupiter is burning with love for the young boy Ganymede. So what does he do? He turns himself into an eagle, swoops down, and carries the lad back up the heavens. To this day, Orpheus says, Ganymede is Jupiter's personal bartender in heaven.
One day, the goddess Venus, who was Aeneas's mother, decides that her son has lived as a mortal long enough. She asks Jupiter for permission to make him a god. Jupiter consents. So, with the help of the River Numicius, who cleanses Aeneas of his mortality, she makes him one.
Later, Mars, the god of war, who is also Romulus's father, asks Jupiter for permission to transform his son into a god. Jupiter is cool with the idea.
Near the very end of the book, Jupiter prevents Venus from saving Julius Caesar from being assassinated. But then he tells her that Julius Caesar will one day become a god. Venus is satisfied with that.