The second Athenian domination started with the definite expulsion of the Delians to Achaia, in the Peloponnese. The declaration of Delos as an "international" harbour by the Romans led to an influx of foreigners who became a significant element of the island's population. The absence of taxes resulted to the concentration of trade activity on the island and, subsequently, to its economic prosperity.
The close relations of Delos with Rome, though, was the main reason for its decline. During Mithridates' wars againts the Romans, Delos suffered severe damage in the raids of 88 B.C. and 69 B.C. Since then, the island's prosperity gradually came to an end. In the 2nd and 3rd centuries A.D. only a small settlement existed on Delos and, as Christianity had gradually replaced the ancient religion, the island finally lost its importance.