Simplify the following text for a Grade 6 native English-speaking person.
Original: Aeschylus was one of many Greeks who had been initiated into the Eleusinian Mysteries , a cult to Demeter based in his hometown of Eleusis .
Simplified: Aeschylus was one of many Greeks who joined the Eleusinian Mysteries . This was the religious cult to Demeter , and based in his home town of Eleusis .