Aeschylus was one of many Greeks who joined the Eleusinian Mysteries. This was the religious cult of Demeter, and based in his home town of Eleusis. Members of the group learned mystical and secret knowledge. Members were sworn under the penalty of death not to say anything about the Mysteries to anyone. Aristotle wrote that some people thought that Aeschylus had shown some of the cult's secrets on stage. Other writers said that an angry mob tried to kill Aeschylus on the spot, but he ran away. Later, Aeschylus said he did not know that he had shown any of the secrets. He was saved from death only because of his brave service in the Persian Wars.