Demeter was the second eldest of the gods and really chill. She was pretty important as a fertility deity, and was often syncretized with other goddesses like Rhea and Gaia and with Roman Ceres and "Phrygian" Cybele. Though she never married, she was no stranger to the arts of love (well, duh, for a fertility goddess). In fact, her priestesses initiated brides and grooms into the "secrets of the couch." While she was still young she and Zeus got jiggy with it and produced Persephone (called Kore, or Girl) and Iacchus (which means Boisterous Shout by the way). The Titan Iasius was her second love interest - they met each other and fell in love at the wedding of Cadmus and Harmonia. After drinking way too much nectar to be good for one's judgement, they left the party and made love openly in a "thrice-ploughed field" When they got back to the party with that "after-glow" Zeus figured out what had happened immediately. The fact that they were both covered in mud in all the wrong places might have aided his discovery just a tad. So, Zeus gets all jealous and throws a thunderbolt at poor Iasius and killed him. Other versions say his brother Dardanus killed him, or that his horses killed him.
This couldn't have been good for Demeter's feelings for Zeus. But she remained a happy goddess, only getting really mad at one person. That person completely deserved it though. His name was Erysichthon, or Earth Tearer. So, this young cocky man led a group of twenty men into one of Demeter's SACRED GROVES. It was planted for Demeter by the Pelasgians at Dotium. This by itself was enough to constitute serious punishment, but it doesn't end there. Apparently Erysichthon was building a new banqueting hall, and hoping to find cheap wood. He started cutting down the sacred trees to provide timber for his little building project. I would have flipped out, personally, but Demeter - the chill goddess that she was - merely took the form of Nicippe (that means Conquering Mare by the way), the priestess of the grove, and calmly ordered him to stop. At that, Erysichthon raised his axe and threatened to cut her down. At that point Demeter had had enough. She changed back to her true form and cursed him to be eternally hunger. The more he ate, the hungrier and thinner he got. He ate his parents out of house and home (literally) and then went to the streets, where he ate the dirt. But she wasn't just punishing. This one guy, Pandareus the Cretan, stole Zeus's golden dog and she gave him the gift of NEVER getting a stomach-ache. Remember, she was bitter about Zeus's anger management problems resulting in a dead lover.
So you see, Demeter was a very happy goddess. Until the day came when Kore, who after this became Persephone, was abducted. When that happened, Demeter lost her joy and went searching the Earth for her. As it happened, searching the Earth wasn't going to do much good. Persephone had been abducted by Hades, and he wasn't letting her go without a fight. Eventually Hermes came down and Hades HAD to let her go, but because she's eaten seven pomegranate seeds she had to stay there for three months out of the year. If you're interested in reading more, you should check out Persephone's page. So, back to Demeter. She went searching for nine days and nights, calling out for her daughter, not eating or drinking. Only Hecate could tell her anything. She recounted a tale of hearing Persephone's voice crying, "A rape! A rape!" and trying to rescue her, but never finding her.
On the tenth day, Demeter went to Eleusis in disguise. There King Celeus and Queen Metaneira entertained her and graciously offered her the position of wet-nurse to their son Demophoon. Iambe, a slave in the house (and the daughter of Pan and Echo), tried to cheer Demeter up with silly lascivious verses (iambic verse probably comes from her efforts). In a related story, Baubo was responsible for cheering the goddess up - she pulled her skirt over her headgoddessoned the Great Mother Goddess - and it worked, the goddess drank her barley water and felt better. Then, an elder son of Celeus, Abas, accused Demeter of greediness while she drank barley water. Without thinking, Demeter threw him a grim look, and turned him into a lizard. Later, she felt bad, and decided to make Demophoon immortal. She put him in her sacred fire, chanting, to burn away his mortality. Unfortunately, Metaneira came in before the ceremony was complete, and Demophoon died. Now that was two sons dead by a goddesses hand, and Celeus began to think his house was cursed. In his weeping his name got changed to Dysaules (which means "of an unhappy house", more or less), and Demeter told him to stop weeping, because she would bestow many gifts upon his third son Triptolemus. So, she makes him "minister of agriculture" (as Bell puts it), but she's still pissed. She is the goddess of fertility and with her anger comes famine and unending winter. And there were months and months of that famine until Persephone was released. And every winter, that lack of growth continues while Persephone spends her time in the Underworld.
This story is famous. It is the myth that we all know surrounding the Mysteries of Eleusis (the place where Persephone was returned to her mother). But the secret myth? Well, it is a secret. The Eleusinian Mysteries intrigue many, not least myself, and I guess in part that's just the nature of mysteries. But there are many mysteries, and many secrets of women, but how many entire cults (religions) and societies deeply are so explicitly linked to them? The Eleusinian Mysteries were practiced throughout Greece for thousands of years - even Heracles was initiated into the Lesser Mysteries (there were two levels of initiation - both secret). Demeter and Persephone were at the heart of those mysteries, and although we will probably never know exactly how, isn't it good to know that the Mother and her Daughter truly were so sacred in their terrifying, nurturing, wonderful way were so sacred to the Greeks? Many people have tried to reclaim some sort of matriarchal prehistory, even me (especially when I was first starting this site and didn't know any better), but I have found that the complicated, probably quite patriarchal, but in many ways unknowable truth of the Eleusinian Mysteries is a much more fulfilling myth to pin my hopes on. Anyway, enough about me, if you wanna read a little more (somewhat academic, but still really good), I suggest the book Eleusis: Archetypal Image of Mother and Daughter, by Carl Kerenyi.