Most of this article will be concerned with the institutional organization of Athens’ public finances, but to provide the background to that I begin with some basic facts about income and expenditure. Athens’ finances, and Athenian administration generally, were on a larger scale and more complex than those of most Greek states – partly because Athens itself was an exceptionally large state, with a territory of 1,000 square miles (2,600 square kilometres) and a body of adult male citizens numbering perhaps 60,000 before the Peloponnesian War and 30,000 after; and partly because, in addition to its domestic business, for much of the fifth century Athens had the business of the Delian League to deal with and for forty years in the fourth century it had the business of its Second League. The Delian League was without precedent in the Greek world as an alliance founded with a view to ongoing warfare, and as an alliance to which many members from the beginning and almost all members after a while made contributions by annual cash payments of phoros (‘tribute’). Athens thus needed to develop skills in managing large and small sums of money to a much greater extent than other states. Athens’ administration depended largely on annually appointed officials, and our evidence gives prominence to the principle of accountability and to various accounting procedures; but, although Athens applied the principles in its own way, the principles were not distinctively Athenian or distinctively democratic: the use of rotating officials and of accounting procedures was widespread in Greek states of varying political complexions.