It is well known that in the fifth century BC, Athens saw the creation of a civilisation remarkable both for its democracy and its architectural magnificence. What is perhaps less well known is that these achievements depended on the existence of a large empire, which the Athenians ruled with tyrannical control, enforced by a powerful navy. How could the birthplace of democracy simultaneously conduct militaristic imperialism? How the Trireme Brought Democracy to Athens explains how the development of democracy led to this paradox.