The settlement of Eleusis was founded in ca. 2000 B.C. on the slopes of the hill, and during the Mycenaean period it developed into a large fortified settlement, mostly due to its strategic position. During this period the cult of Demeter was introduced, as the worship of a deity connected to nature and the growing of cereals. The continuity of Demeter's cult is attested until Roman times, by the erection of successive temples on the east side of the hill.
In the 8th century B.C. the sanctuary aquired a panhellenic character, and in the time of Solon, the Eleusinian Mysteries were established as one of the most important Athenian festivals. During the tyranny of Peisitratos the sanctuary and the settlement were enclosed with a massive fortification wall reinforced with towers. Splendid buildings were erected during the Classical and Roman periods, but with the spread of Christianity and especially after the invasion of the Ostrogoths, the sanctuary was abandoned.