Attica, as the area surrounding the city of Athens is called, smaller than many modern US counties, but larger than most of the other Greek poleis. The Athenians enjoyed an advantage of natural resources: rich silver mines at Laurion in southeastern Attica. Athens had not only some advantages in geography and resources but also favorable historical circumstances and remarkable leadership on its side. Interrupted by only two brief periods of oligarchic rule during the fifth century BCE, the Athenian government was characterized by a participatory system that had come to be called demokratia. A key to understanding the reasons for the remarkable expansion of political enfranchisement lies in the connection between political rights and military service. The city of Athens was not just a political and military center; it was also the focus of a commercial empire that controlled trade in the Aegean. Education was key to power and wealth in a litigious, participatory democracy.