In Greek mythology, Demeter goddess of harvest was the second daughter of Cronus and Rhea. Just like her siblings Hestia, Hera, Hades and Poseidon (with the exception of Zeus), she was swallowed by her father at birth and she was later brought up when he took an emetic given to him by Metis.
Later, she joined the other gods in their war against the Gigantes (also called the Gigantomachia). She was depicted as yielding a golden sword (a khrysaor).
She was the goddess of agriculture, harvest, grain, milling and bread, of fruit in general (figs, pears, apples) and also the goddess of divine law, as agriculture means bringing order in nature and following rules. The second part of her name, meter, means "mother", while the first part De (which in Doric was Da) is supposed to be a form of the word Ge, which means "Earth" (yes, it's the name of the goddess Gaia). This means that her name, De-meter or Da-meter, might be translated as "Mother Earth". She was also called Thesmophoros, which means the Law-giver.
Being a goddess of the fertility of the earth, she was also considered a goddess of fertility in general and she was worshipped as a goddess of marriage. Her wrath, though, was terrible, as she would bring hunger to those who offended her.
She was often depicted as a mature woman, similar to Hera, but with the eyes less wide open; usually she was seated, with a crown on her head, holding wheat-ears or a cornucopia. She would ride a chariot pulled by two winged serpents.
Demeter goddess of harvest was the first one to put oxen in a yoke and to plow the land. She discovered wheat when she was pregnant with Persephone but, after her daughter was abducted, she got angry and burned all the seeds. After she reconciled with Zeus, she gave Triptolemus the wheat and taught him how to sow it. In the cities that she visited, she gave people laws and rules.
Demeter was the mother of goddess Persephone, by her own brother, Zeus (I couldn't find any more info about this). Anyway, I came to the conclusion that she raised her daughter alone, without any help. And when her daughter grew up and became a beautiful maiden, guess what? Her uncle Hades falls in love with her and Zeus tells him to just kidnap the girl, because her mother would never agree to let her marry someone who spends his time underground. Can a father be more horrible than that? (Answer: Yes, he can, if he is Zeus!)
While Persephone was playing in a meadow and picking flowers, the earth opened and she was swallowed by it. Her mother just heard a cry and that was all. She started to ask everyone if they knew anything about her daughter, but it was in vain.
In despair, she put a dark cloak on her shoulders and started to look for her daughter, with torches in her hands. She walked and walked without tasting ambrosia or nectar and without washing, until she arrived in the West, where the garden with the golden apples was. She crossed the river Achelous three times in her frenetic search, yet she couldn't find her beloved daughter. After nine days of search, goddess Hekate told her that she heard the girl screaming, but she didn't know who took her.
Demeter and Hekate went together to Helios and asked him if he knew anything about that. The Sun god told them that it was Hades who took Persephone, but anyway he was a worthy husband, being from a good family (the same as Demeter's, as they were brothers) and also being very rich (when Zeus, Poseidon and Hades divided the world, the last one got one third of everything).
Demeter was so upset, that she disguised himself as a old woman and went to Eleusis. She stopped near a well and sat on a rock. The daughters of king Celeus (Callithoe, Callidice, Cleisidice and Demo) saw her in distress and invited her to the palace, where the other women would make sure that she was well received.
Demeter the goddess told them that her name was Doso and that she was kidnapped from the island of Crete by the pirates. When they stopped on a shore to get water, she managed to run away and now she didn't even know where she was. She asked them to direct her to a house where she could work, either by nursing a baby or as a servant.
Callidice told the goddess it was better to come directly to their house and help their mother, Metanira, with her last-born, a baby-boy. The goddess agreed, so the girls took water from the well and went back home, to tell their mother about this woman. Metaneira agreed to hire her and the girls returned with the good news at the well, where the goddes was waiting.
When goddess Demeter entered the king's house, a heavenly glow filled the doorway. Metanira understood that the old woman was from a noble family. The goddess sat down on a chair where an old woman, Iambe, had put a fleece. She was so sad, that she remained in silence for a long time. But Iambe kept making jokes, until she managed to make the goddess smile.
Metanira offered Demeter a cup of sweet wine, but the goddess told her to mix meal and water with soft mint and give her to drink. That's why this was the beverage that the initiates drank afterwards, in the Eleusinian Mysteries.
Metanira asked goddess Demeter to help her raise her son until he reached full youth. She had prayed a long time before she managed to had a boy, and so her son was very precious to her. Demeter promised to take good care of him and to protect him from witchcraft and illnesses.
The goddess would annoint the little Demophon with ambrosia by day, as if he were a god's child, and would keep him in the fire at night, so as to make him immortal and ageless. His parents were amazed at how quickly their son grew. One night Metanira spied on Demeter and saw her holding him in the fire. She was so afraid, that she cried, and the goddess took the child out of the fire and threw him on the ground.
Demeter was very angry with the quen; she swore by the waters of the Styx that her intention was to make the child immortal, but now he had no escape from fate and old age. She also told Metanira to build a temple for her, where the goddess would teach them her rites, which they had to perform dutyfully, if they wanted to be forgiven.
Demeter shed her mortal form and took her goddess look - all of a sudden she became young and beautiful, her body was spreading light and a beautiful fragrance. Metanira remained speechless and didn't even have the force to take the baby in her arms.
Alarmed by Demophon's crying, his sisters came, took him in their arms and washed him, but he kept on crying, because none of the nurses and the maids attending to him were not as skilfull as Demeter.
In the morning, they told king Celeus about the goddess' request. He assembled a lot of people and ordered them to build the temple as quick as possible.
Demeter sat in the temple for a year, mourning for her daughter. She decided to punish mankind and so she kept all the seeds from sprouting. This brought famine all over the place. People were desperate, and Zeus was desperate, too, because nobody had anything to bring as a sacrifice to the gods.
Zeus sent Iris to summon Demeter to Mount Olympus, but the goddess refused. He sent other messengers with beautiful gifts, but she just wouldn't listen. She swore not to return to Olympus or let the fruit spring forth until she saw her daughter again.
When Zeus heard this, he sent Hermes, the messenger of gods, to Hades, to try and convince him to release the girl, or else Demeter plans to destroy all humans by keeping the seeds hidden beneath the earth.
Hades agreed, but he had thought about everything beforehand - as Persephone was sad because she missed her mother, she didn't want to eat anything. Hades forced her to eat the seed of a pomegranate.
Persephone was overjoyed to go back to her mother. She leapt into Hades' goden chariot, while Hermes took the reins. He took the girl to her mother's temple. When Demeter saw her beloved daughter, she ran towards her like a Menad (i.e. like a crazy woman). They hugged and the mother couldn't take her eyes away from her daughter.
All of a sudden, Demeter felt a sting in her heart. She asked Persephone if she had eaten anything while she was in the Underworld. If she hadn't, she could just remain with her mother and father in Olympus forever. But if she did, she had to stay underground for one third of a year and, in spring, she would come up and be with her mom.
Persephone told her mother about how she was abducted and how it was all Zeus' idea.
Goddess Hekate came near them and hugged Persephone, too. Later she would become her faithful companion in the underworld.
Zeus then sent Rhea, their mother, to tell Demeter to join the gods. Rhea came to the plain of Rharos, which once was fertile land, but now was barren. She was very happy to see her daughter and her granddaughter. She told them that Zeus had decided that Persephone should stay with Hades underground, for one third of the year, and then she should spend two thirds of the year with her mother, on the surface of the earth (this myth is, in fact, an explanation of the seasons: winter, spring and summer, because ancient Greeks only had three seasons). Demeter was so happy with the ruling, that she made leaves and flowers spring everywhere.
The goddess of harvest gave Triptolemos the seeds of the wheat and instructed them how to sow them. He took her chariot driven by winged snakes and spread the seeds all over the land. After that, the goddess taught him and his father how to perform her rites.