The Dodecanese are a group of 12 larger plus 150 smaller Greek islands in the Aegean Sea, of which 26 are inhabited. Τhis island group generally defines the eastern limit of the Sea of Crete. They belong to the Southern Sporades island group. They have a rich history, and many of even the smallest inhabited islands boast dozens of Byzantine churches and medieval castles.
It is in the Dorian period that they began to prosper as an independent entity, developing a thriving economy and culture through the following centuries. By the early Archaic Period Rhodes and Kos emerged as the major islands in the group, and in the 6th century BC the Dorians founded three major cities on Rhodes (Lindos, Kameiros and Ialyssos). Together with the island of Kos and the cities of Knidos and Halicarnassos on the mainland of Asia Minor, these made up the Dorian Hexapolis.
This development was interrupted around 499 BC by the Persian Wars, during which the islands were captured by the Persians for a brief period. Following the defeat of the Persians by the Athenians in 478 BC, the cities joined the Athenian-dominated Delian League. When the Peloponnesian War broke out in 431 BC, they remained largely neutral although they were still members of the League.