In this article we shall study the notion of ‘empire’ in classical Greek political thought. Our aim is arguing that such a concept establishes a notion of empire in which live together the ideas of legitimate authority and of despotic domination. This is important because we seek to register that notion within the Greek worldview, avoiding comparison with the Modern conception. Finally, we assert that both ways of conceptualizing the notion of empire emerge from the extant tension within the State between the egalitarian volition of the polis and its expansionist targets.