Some say Orion was the gigantic son of Euryale (one of the Gorgons) and Poseidon. But there is another story of his birth, told to explain his name. In this, there was a poor beekeeper, Hyrieus, who had never had a son. He was an old, old man, and impotent, so he had given up hope, but never forgotten his dream. Zeus and Hermes dropped by one day, and the beekeeper let them in and was hospitable. The gods offered him whatever he wanted and the old man responded that what he wanted was impossible. Of course, the Gods have talents with the impossible and after hearing his desire they told him to sacrifice a bull, pee on its hide, and bury it in his wife's grave. He followed these strange instructions to the letter, and nine months later a bubbling baby boy appeared. Hyrieus named the boy Urion, or "he who makes water," but this eventually changed to Orion. That works out perfectly since the times Orion's constellation rises and sets are rainy seasons. Anyway, back to the story. Orion was most well known for his relationship with Artemis, but that was only one part of his life. Artemis was not even his only love - she wasn't even his first or second - but I'll explain that later. Let's begin at the beginning, shall we?
Despite Orion's divine parentage, he was mortal - a mortal of unusually large size, true, but a mortal nonetheless. He became a fabulous hunter, and before he was full grown was known all across Mesopotamia for his skill. But man cannot live by hunting alone - he needed a girl. First, he fell in love with Merope, the daughter of the King of Chios and the granddaughter of Dionysus and Ariadne, so they shared a divine background. Orion is totally into Merope, and wants to marry her, but the King isn't so into the idea of having a grandson about four times his own size. So Orion goes and volunteers to work for King Oenopione (that was his name - crazy, huh?) do get on the King's good side. Unfortunately that wasn't too successful. Even more unfortunately, Orion wasn't a very patient guy and not so nice, after all, because when he got tired of waiting, he just raped Merope.
The King was not too pleased about the situation, but, seeing as Orion was huge, he didn't try to confront him. Instead, he waited for his chance and (honoring his own father, Dionysus) got Orion dead-drunk. When Orion passed out, Oenopion gouged out the giant's eyes and put him out to sea.
Orion just wandered around for a good portion of his life, until the day he bumped into Hephaestus - not too suprising since Hephaestus' lameness made him keep a look out for others like him. Hephaestus took pity on Orion and gave him an assistant to help him get around. With the boy (named Cedalion) sitting on his shoulders to give directions, Orion walked east until he came to the end of the Earth where the Sun rises. There, the sun's rays healed Orion's vision. Now that he could see again, Orion was about to walk home when Eos saw him and swooned. She plucked him off the Earth and carried him in her chariot to Delos.
Eos may have been carrying him off to have him for herself, but she made a boo-boo. This great hunter met Artemis while he was there, and they started spending all their time together. They went on tons of dates, and romance sparked while they were skinning their catches. How sweet. He was the only one Artemis ever even started to love, but that too turned sour.
Some say she accidentally hit him with a discus, but that's too boring. Some say that he tried to rape one of her attendants, Opis, but Gaia wasn't having any of that and sent an enormous scorpion after him. I kind of side with this story, since there is a story about how the Scorpion was placed in the sky, and Orion on the other side, and they chased each other across the sky, never up at the same time. But there are other stories, too. Some say that Apollo was jealous, but knowing that his sister wouldn't let him kill her boyfriend, he merely waited until he could trick her into doing it. He challenged her to target practice while Orion was swimming in a pond, and though the Goddess could barely see her target (and certainly didn't know it was Orion), she shot him and killed him on the spot. Anyway, Orion got put up in heaven with his dog at his side, and all through eternity he chases the Pleiades (including Merope).