Persephone was the daughter of Demeter, the Goddess of Vegetation. One day while Persephone was playing in the fields of Sicily, she spied a beautiful flower. As she picked the flower, the earth opened up and a chariot appeared. The chariot was driven by Hades, the God of the Dead and King of the Underworld. Hades abducted and raped Persephone carrying her deep in to the Underworld. One of Persephone's friends - Cynane 1 (a Naiad) opposed Hades but could do nothing against the God and, out of pain, dissolved away in tears.
Demeter soon realized that her daughter was missing, and searched for many days and nights, but was unable to find Persephone. Finally, she went to her brother Zeus, the King of the Gods and father of Persephone, to ask where their daughter had gone. Zeus replied that none of the Gods of Olympus knew where Persephone was and that he would not help Demeter find her.
Demeter mourned for her daughter for an entire year. During this time she did not bless the crops. The crops did not grow and food was scarce. Demeter became a mortal in an effort to find Persephone and one day she stopped at a fountain. Hearing her cries, the fountain - who was once the Naiad who tried to oppose Hades' abduction of Persephone - tells Demeter what happened to Persephone and that she had become Queen of the Underworld. Demeter returned to the Gods of Olympus. To put an end to the starvation on earth, Zeus decided to assist Demeter in her search. If all the mortals died, there would be no one left to worship the gods. Zeus ordered Hades to return Persephone on the condition that she had eaten no food due to her uncontrollable grief at being separated from her mother.
Hades knew of this condition so before returning Persephone, he made her eat 6 seeds from a pomegranate - the food of the dead. Hades knew that anyone who had eaten the food of the dead was doomed to return to the Underworld.
Zeus sent Hermes (the messenger to the Gods) to negotiate a compromise with Hades. Because Persephone had not eaten the seeds willingly, Persephone was allowed to return to earth to be with her mother for 6 months of each year (Spring / Summer) and had to return to Hades as Queen of the Underworld for the other 6 months (Autumn / Winter).