Historians since Herodotus and Thucydides have claimed that the year 483 BCE marked a turning point in the history of Athens. For it was then that Themistocles mobilized the revenues from the city's highly productive silver mines to build an enormous war fleet. This income stream is thought to have become the basis of Athenian imperial power, the driving force behind its democracy and the centre of its system of public finance. But in his groundbreaking...