Delos was to Family Island, first as a religious center and later as a busy commercial port. In turn it was glorified, lauded, destroyed, rebuilt and destroyed once again; a rich history which lasted several hundreds of years.
Archaeological excavations confirm that the island was inhabited during the second half of the third millennium B.C. Traces of a small prehistoric settlement with circular huts, built either by fishermen or pirates, were found on the summit of Mt Kynthos (112,60 m). From there the first inhabitants enjoyed the security of being able to survey both the sea and the valley below. We have no way of knowing for sure who they were, Kares perhaps, who had come from Asia Minor as claimed by the historian Thucydides, although this has not been proved scientifically. It is also more than likely that the inhabitants of Minoan Crete visited the island. After that first settlement was abandoned and until the beginning of the Mycenaean Age (c. 1600 B.C.), as with other Cycladic islands, no evidence has been found of man’s presence on Delos.
Later, during the second half of the second millennium, the Mycenaeans arrived and settled by the harbor. Following the collapse of the Mycenaean world due to invasion by the Dorians (c. 1100 B.C.), the Ionians settled on many Aegean islands and along the Eastern coast of the Aegean Sea, bringing with them the worship of Apollo, which was introduced also on Delos, and by the 7th century B.C. Delos had become the chief religious sanctuary of all the Ionians, and magnificent religious observations and festivals took place on a regular basis.
The first Ionians who attempted to impose their authority on the sanctuary of Delos were the Naxians in the 7th century B.C.; they erected a great many buildings and countless offerings were dedicated to the god. The Oikos of the Naxians, the Colossus of Naxos and the renowned Terrace of the Lions are the best known of these. During the second half of the 6th century B.C. Paros, another neighboring island had an important role to play in the affairs of the sanctuary for a while. In the same century, just after 540 B.C., Peisistratos, the tyrant of Athens, also became involved in the running of the place as the result of some oracle, and he ordered a “purification”, in other words the removal of all burial monuments from the area around the sanctuary. The tyrant of Samos, Polykrates, also interested himself in Delos and actually dedicated the nearby island of Rheneia to Apollo, joining it literally to Delos with a huge chain.
During the period of the Persian Wars, the Persians respected the Delian Apollo, the sanctuary and its people. One year after the end of the wars, in 479, the Athenians founded a maritime league (the Delian Confederacy, later to be known as First Athenian Confederacy), which was an alliance between the Athenians on the one side, and the Ionian cities and the islands of the Aegean on the other, with Delos as its headquarters. The purported aim of the alliance was to create a united defense against the Persians, but in fact it was the means by which the Athenians would establish their hegemony in the Aegean Sea and gain control over the sanctuary of Delos.
The members of the alliance were obliged to pay an annual tariff and the funds were kept in Apollo’s temple on the island. Athens then became the undisputed master as far as the running of the sanctuary was concerned, with its administration in the hands of Athenian overseers, the Amphictiones. Thus, both as the birthplace of Apollo and as the headquarters of the league, Delos acquired a conspicuous position in the Greek world. Devotees poured in from all over to worship at the sanctuary, to bring offerings and to attend the Delia, the festival which, from the year 426 B.C., was celebrated every four years in honor of Apollo and which included athletic competitions, horse and chariot races, musical contests, and ended with theatrical plays and banquets. However, in 454 B.C. the Athenians transferred the common treasury to Athens, the new headquarters of the alliance, thus drastically weakening the role of Delos.
Furthermore, after a plague hit Athens at the beginning of the Peloponnesian War and was regarded as a sign of Apollo’s wrath, and as a consequence of which (or, to be more accurate, using this as an excuse), the Athenians decided on a second purification of the island: all the tombs on Delos were opened, with the exception of only a few which were considered sacred, and the bones and the funerary offerings were transferred to a mass grave on the neighboring island of Rheneia. A law was also passed forbidding thenceforth both births and deaths on the sacred island. As a result, expectant women and the dying were carried at once to Rheneia.
The explanation is simple: if a person was neither born in a place, nor were his ancestors buried there, then that place could hardly be considered his homeland, nor could he claim it as his own. This was precisely what the Athenians were aiming for in order to make themselves masters of Delos. In 422 B.C. the purification was completed when the Athenians banished all the native Delians to the town of Adramytion in Asia Minor, on the pretext that they were “impure”, and where the Persians slaughtered many of them. The survivors would later be led back to Delos by the Athenians due to a certain warning by the oracle of Delphi.