Delos underwent a rapid economic development after 167 BCE, when its Roman rulers granted the port of Delos ‘duty-free’ status under Athenian dominion and turned it into a commercial base connecting the eastern and western Mediterranean. The island became a free-trade commercial base under nominal Athenian supervision, but essentially under Roman rule. The result of this economic development was an unprecedented population increase and, by consequence, accelerated urbanization – changes attested by the formation of new neighborhoods and harbour facilities and the redevelopment of existing urban and harbour areas of the island. This presentation will discuss the island’s urban development, maritime infrastructure, and its commercial connections in order to shed light on this important key site in the history of Hellenistic Greece and the nascent Roman Empire.