Jupiter All the gods knew that Hercules was half man and half god. His mother was a mortal. But his father was a king - the king of all the gods, the mighty Jupiter. But Hercules did not know he was part god until he had grown into a man.
Juno, Jupiter's wife, was very jealous of Hercules. She tried all kinds of ways to kill him, including sending a couple of really big snakes into his crib. He was just a baby, but Hercules crushed those snakes. Hercules was incredibly strong, magically strong, and he knew danger when he saw it, even as a baby!
Jupiter admired strength. He loved his little son. He figured that sooner or later, Juno might actually find a way to kill little Hercules. To keep Hercules safe from attack, Jupiter sent him to live with a mortal family on earth.
Hercules grew up loved and noble. But he didn't fit in on earth. He was too big and too strong. One day, his earth father told him he was a god, well, part god anyway.
The rest of the story of Hercules is a series of stories, tasks, and adventures, as Hercules earned his way into the heavens, to take his place with the gods.
As the story goes .....
Eurystheus was the mortal cousin of Hercules. He hated his cousin, Hercules. When Juno offered to help Eurystheus design 12 Labors (missions or tasks) that Hercules had to complete, tasks that could get Hercules killed, Eurystheus jumped at it.
Hercules believed that when he had completed the 12 missions, he would have earned immortality. That's what the Oracle at Delphi had said. Actually, the oracle had said, "If you complete 12 Labors, immorality will be yours." Of course, being an oracle, she never explained what she meant by "immortality" - would he live forever in legend or for real? Hercules never asked. (She would not have told him anyway.)
Eurystheus did not want Hercules coming after his crown. It would never have occurred to Hercules to do so. But an evil little man like Eurystheus would never have believed that. Each time Eurystheus and Juno gave Hercules a task to accomplish, they were sure that Hercules would never live through it.
But Hercules surprised them. He not only lived, he had great adventures, discovered true friends, and rid the world of some really nasty critters.