Demeter, the middle daughter of Cronus and Rhea, was the Ancient Greek goddess of grain and agriculture, one of the original Twelve Olympians. Her grief over her daughter Persephone, who has to spend one-third of the year with her husband Hades in the Underworld, is the reason why there is winter. Demeter's joy when she gets her daughter back coincides with the fertile spring and summer months. Demeter and Persephone were the central figures of the Eleusinian Mysteries, the most famous secret religious festival in Ancient Greece.