Delos won early acclaim as the mythical birthplace of the twins Apollo and Artemis and was first inhabited in the 3rd millennium BC. From the 8th century BC it became a shrine to Apollo and the oldest temples on the island date from this era. The dominant Athenians had full control of Delos – and thus the Aegean – by the 5th century BC.
In 478 BC Athens established an alliance known as the Delian League, which kept its treasury on Delos. A cynical decree ensured that no-one could be born or die on Delos, thus strengthening Athens’ control over the island by expelling the native population.
Delos reached the height of its power in Hellenistic times, becoming one of the three most important religious centres in Greece and a flourishing centre of commerce. Many of its inhabitants were wealthy merchants, mariners and bankers from as far away as Egypt and Syria. They built temples to their homeland gods, but Apollo remained the principal deity.
The Romans made Delos a free port in 167 BC. This brought even greater prosperity, due largely to a lucrative slave market that sold up to 10, 000 people a day. During the following century, as ancient religions lost relevance and trade routes shifted, Delos began a long, painful decline. By the 3rd century AD there was only a small Christian settlement on the island, and in the following centuries the ancient site was looted of many of its antiquities. It was not until the Renaissance that its antiquarian value was recognised.