The Rites of Eleusis, or the Eleusinian Mysteries, were the secret rituals of the mystery school of Eleusis and were observed regularly from c. 1600 BCE - 392 CE. Exactly what this mystic ritual was no one knows; but why the ancient Greeks participated in it can be understood by the testimonials of the initiated.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/32/the-eleusinian-mysteries-the-rites-of-demeter/.