The Greater Mysteries was an annual celebration held in the Attic month of Boedromion (September-October). Preparations for the festival began several weeks earlier with the sending of messengers to the Greek city-states to declare a sacred truce. The hierophant chose the messengers from among the members of the sacred gene of Eleusis, the Eumolpidae and the Kerykes. The ceasefire lasted fifty-five days, from the fifteenth day of Metageitnion (the month before Boedromion) to the tenth day of Pyanepsion, which followed the month of the Mysteries. Every four years, the celebration took place with great splendour.

Pyre Γ. Blac-figure hypocreterion (base of a lebes) depicting a ceremonial procession, mid-6th century BCE, vessel, Εν Αθήναις Αρχαιολογική Εταιρεία © Η εν Αθήναις Αρχαιολογική Εταιρεία

Pyre Γ. Blac-figure hypocreterion (base of a lebes) depicting a ceremonial procession, mid-6th century BCE, vessel, Εν Αθήναις Αρχαιολογική Εταιρεία © Η εν Αθήναις Αρχαιολογική Εταιρεία