This paper explores the role of natural resources in the expansion and transformation of the Delian League into the Athenian empire, concentrating on two particularly resource-rich regions, Thasos and the Black Sea coast. Thasos was well-known in antiquity for its valuable precious metal resources, among others, and the Black Sea was likewise renowned for its grain, as well as human and metal resources. These two regions are also related insofar as Thasos was in a strategic location for ships hugging the coastline on voyages from the southern Aegean to the Black Sea. This paper will investigate whether Athenian interest in natural resources could have played a significant role in shaping Athenian policy, and thus affected the development of the Athenian empire. The copious amount of scholarship on the transformation and expansion of the Athenian empire indicates that it cannot be simplistically reduced to a single factor or cause, and the pursuit of natural resources cannot explain or justify the Athenian empire by itself. Nevertheless this paper will show that the Athenian pursuit of natural resources could have affected the events of the 5^th century, and ignoring the pursuit of natural resources in the development of the Athenian empire would minimize a significant factor in the interpretation of its motives and causes.