The smallest of the Cyclades, this island was the mythic birthplace of both Apollo and Artemis. The island was also an independent polis and had a large Pan-Hellenic religious center. The Ionians considered it their holiest site.
The island was chosen to be the first center of the Delian League, and the treasury of the alliance was kept on it until it was transferred to Attica as Athens was becoming not only the senior member of the alliance but actually its mistress.
In the Peloponnesian War the city of Delos was destroyed, and according to legend, since then it is forbidden to sleep on the holy island, as it incurs the wrath of Apollo.