Mythic, worshipped in ancient Greece, exact dates uncertain, by 1500 B.C.E.
Demeter was goddess of the harvest and associated with the changing of the seasons. A friend to humankind, she taught them agricultural skills. Her festival took place in September, during the harvest. Eleusis, a small town near Athens in the heart of the wheat and barley growing region, was the location of her great temple, and her festival is referred to as the Eleusinian Mysteries, since the climax of the ceremony involved secret rituals. The Mysteries are thought to have been established in the 1500s B.C.E. and were held annually for 2,000 years. So pervasive was Demeter’s influence on Greek life that men, women, and even slaves participated in her festival.