The hero Perseus in Greek mythology was the son of Danaë and Zeus, who had turned into a stream of gold in order to get into her chambers. But the story is long, let's start with the beginning!
Acrisius, the king of Argos, had a daughter, Danaë, but he wanted badly to have a son, too. He asked the Pythian oracle about this, and he found out that his daughter would have a son who would kill him. Afraid of what he heard, he decided to build a bronze chamber underground and he locked Danaë in there, in order to prevent her from having children (she was not married).
But Zeus, who could see everything, noticed the beautiful girl and fell in love with her. In order to get to her, he turned into a shower of gold which dripped inside from the ceiling. (Of course, we all know that Zeus could transform into anything he wanted to, in order to get near a lady. In this case, the shower of gold was also interpreted as the power of money over the heart.) There is also another version, according to which Perseus' father was in fact Proetus, Danaë's uncle, twin brother of Acrisius.
Anyway, when king Acrisius discovered that his daughter had a son, he was very furious. We don't know whether he really believed that Perseus was Zeus' son. Even if the little one was his brother's son, he had no reason of being happy. Anyway, he just couldn't kill them, so he decided to put the mother and child into a chest and threw it into the sea.
Danaë prayed a lot to be saved and Zeus guided the chest to the shores of the island of Seriphos/Seriphus, in the island group of the Cyclades. There, a fisherman called Dictys saw the chest floating and pulled it ashore.
The Greek playwright Aeschylus wrote a play about this moment, called The Net-Draggers. In the fragments that remained from this play, we see Dictys asking the Satyrs for help, because he could not pull by himself the chest to the shore. The Satyrs would like to keep Danaë with them, but she prays Zeus to help her, saying: "The fault is mainly yours, yet I'm the one who has to pay".
Dictys was poor, but he did his best and raised Perseus like his son. Growing up, the boy became very strong and courageous... and he was handsome, too!
But Dictys has a brother, Polydectes, who was the king of the island. The kinf fell in love with Danaë and wanted to make her his wife, but Perseus would protect his mother all the time. That's why Polydectes thought about a stratagem, in order to send Perseus on a wild goose chase.
He invited his friends - and Perseus, too - to a banquet, where he asked them to bring him gifts, because, he said, he wanted to ask Hippodamia in marriage. Everyone agreed that horses were the best gift for her, as her very name meant "tamer of horses". Only Perseus was so poor, that he could not bring anything. But he declared he was ready to go and look for whatever gift the king wanted... and that's how Polydectes tricked him into bringing Medusa's head.
Click here for the story of Perseus and Medusa.
Click here for the love story of Perseus and Andromeda.
Here you can see pictures of Perseus slaying Medusa.