Demeter, goddess of the harvest, was Zeus' sister. While many of the Greek goddesses were "adopted" into Greek religion from other cultures, the cult of Demeter seems to have originated in Greece. Her cult was centered on the town of Eleusis, where the Eleusian Mysteries were held in honor of Demeter and her daughter each year. Demeter had a daughter with Zeus named Kore. Kore quickly became associated with, and then merged with, Persephone , a pre-Greek goddess of the dead.
Demeter was responsible for bringing crops to fruition, both wild and cultivated. If she did not give her blessing to the earth, famine and starvation would follow. In the myths, Persephone was kidnapped by Hades , god of the underworld, to be his queen. Demeter was so stricken that she disguised herself as an old woman and wandered the earth, seeking her lost daughter. Eventually she came to Eleusis, where a local ruler took her into his home. Zeus, knowing that if his sister was not given aid, the mortal world would perish, sent Hermes to bargain with Hades for the return of the sunny Persephone. Hades slyly told Persephone that she was free to go -- and then gave her a handful of pomegranate seeds to eat if she was hungry on the way back to the surface. Persephone ate four seeds, and thus she was bound to spend four months of the year with Hades in his dark kingdom. During that period, Demeter was so sorrowful that she allowed the earth to grow barren and the plants to wither despite the bright sun. The myth of Demeter explains why the harsh Greek summers rendered crops and wild plants alike unproductive, and also why Eleusis was a special place for the cult of Demeter.
