For the greeks Ceres was the Mother Goddess of the Earth. Seduced by Zeus she had a daughter from him, Persephone. Persephone happily grew up among the other daughters of Zeus, but being extremely sweet and beautiful her uncle Hades fell in love with her. One day while Persephone was picking flowers (the leyend has it it was a narcissus) the ground opened and Hades appeared and dragged her down into the Underworld. Persephone cried out as she dissapeared but, while hearing her cry, when Ceres arrived to the place there was no sign of Persephone anymore. For nine days and nine nights Ceres wandered around the world with a lighted torch on either hand, looking for her beloved daughter. Only in the tenth day she met Helios, who sees everything, and he was able to tell her what had really happened. Ceres decided to abandon her divine role until her daughter was returned to her.
Ceres self imposed exile from the divinities made the Earth sterile,
so Zeus ordered Hades to return Persephone. But that was no longer
possible. During her stay in the Underworld Persephone had eaten a
pomegranate seed which linked her for ever to Hades. A compromise
was reached by which Ceres would return to Mount Olympus and Persephone
would divide the year: half with her mother and the other half in
the Underworld. This is why when Persephone leaves the Underworld to
be with her mother the Earth blossoms, bringing Spring and Summer to the
mortals as a sign of the joy of both deities. When time comes for
Persephone to leave her mother for the Underworld, autumm and winter
cover the Earth in sign of grieve.