Greek goddess of grain and agriculture; mother of Persephone. Defined by the Eleusinian Mysteries — the most important mystery cult of the ancient Mediterranean, attended for roughly 1,500 years until closure by Theodosius I in 392 CE. The Homeric Hymn to Demeter narrates her search for the abducted Persephone, the founding of the Mysteries at Eleusis, and the seasonal cycle.