Like the Dionysian mysteries, the very popular mysteries of Eleusis were in some sense related to the processes of nature—the planting and harvesting of grain—and by extension, the possibility of life after death. It is thought that the mysteries originated in Minoan Crete or in the stories of Isis and Osiris and Horus in Egypt. Whatever the origins, the mystery cult seems to have existed at least as early as the Early Mycenaean Age. The mystery sanctuary was built in Eleusis, a small city near Athens, in about 1500 B.C.E. Like the Dionysian rites, the secret mysteries, which remain somewhat unknown, apparently involved intoxicants, processions, music, and dancing, and perhaps even the sacrifice of an animal.

The myth behind the mysteries is that of Demeter, particularly the loss of her daughter Persephone (Kore), her search for her daughter, and her daughter’s return.

After Persephone was taken by Hades, Demeter separated herself from her Olympian relatives and searched the world for her. At Eleusis she disguised herself as an old woman and became nurse to the infant prince, Demophon. Each night Demeter rubbed the boy with ambrosia, the food of the gods, and set him in a fire to burn away his mortality—all of this to give him eternal life. But when the horrified queen saw her son in the fire, she pulled him out of the flames. Now Demeter revealed who she was and demanded that a temple be built for her in Eleusis where she would teach the people her rites leading to life after death.