Demeter.
They were Mysteries and not told to those not instated into the cult.
Demeter's worship is known as the Eleusinian Mysteries.
Demeter was primarily worshipped in the city of Eleusis in ancient Greece. The Eleusinian Mysteries, dedicated to Demeter and her daughter Persephone, were held there and are among the most famous religious festivals in ancient Greece.
Probably the Eleusinian Mysteries to honor Persephone and her mother, Demeter.
The Telesterion at Eleusis was one of the primary centres of the Eleusinian Mysteries.
Triptolemos is a god of the Eleusinian mysteries who presided over the sowing of grain-seed and the milling of wheat.
The Eleusinian Mysteries (the cult of Demeter and Persephone) were the most famous of the secret religious rites of ancient Greece.
Victor Magnien has written: 'Les mysteres d'Eleusis' -- subject(s): Eleusinian mysteries
Deity Dangerous Deo ("of the earth")
He learned how to enter and exit the underworld unharmed by being initiated in the Eleusinian mysteries.
It could be Eleusina where the Eleusinian Mysteries, one of the most important religious event of Ancient Greece, took place in her honor.
Triptolemus was not really a ruler. He was the son of King Celeus of Eleusis in Attica, and was one of the original priests of Demeter. He gained the knowledge of the Eleusinian mysteries.