Should we care about the size of the population of classical Athens? And if so, why? To what extent can we quantify it, and how best should we attempt such quantification? In this chapter I consider both some influential answers to those questions that have been provided by ancient historians in the past, and some reasons for questioning and rethinking those answers.

Most fundamentally: should we care? Some historians at least would answer quite positively ‘yes’, for basically two reasons. First, we are interested in classical Athens today partly, even principally, because of its dēmokratia. How we understand the operation of Athens’ political institutions depends to an extent on how many citizens there were. If, for example, an ‘average’ meeting of the assembly had an attendance of about 5,000, what proportion of the total citizen body was that? If it was only possible to serve twice on the boule, how many citizens would have experience of working in this important body in their lifetimes, and so how knowledgeable and experienced might those assembly-goers be? Second, population size is obviously relevant to discussions of the Athenian grain trade, where a key issue of debate has been the extent to which Athens had (or did not have) a structural need for imported food because it had more people than its own agricultural resources could support. While there is some intrinsic interest in this question it has fairly obvious wider implications for the development of economic institutions in Athens, for the interconnectivity of the Greek world (and beyond), for Athens’ external relations and foreign policy, and for its internal politics.