Today, friendship and politics are most commonly viewed as distinct and mutually opposed concerns. Politics tends to be seen as general and impersonal, to do with Power and Hierarchy. Friendship, by contrast, is standardly conceived as particular and intimate, relating to Equality and Fraternity. On this view, friendship may corrupt politics, and politics override friendship. Ancient thought, however, as in Greece and Rome, tended to bring the two together, locating friendship as the moral foundation of the political. This view of the two as linked, moreover, has tended to obtain across the world, especially in early social systems. But is that view sound? Ought not Friendship to be dismissed by moderns as primitive, inefficient, nepotistic (Freud)? Or ought it to be promoted as a vital moral constraint on Power and the consuming egotism of rulers (Plutarch and others)? This volume seeks to answer, directly and indirectly, by supplying (i) analyses of the concept, (ii) critical reconstructions of some crucial modern accounts (Kierkegaard, Arendt and Schmitt) and (iii) concrete accounts of the actual play of friendship both within and between states. It throws light on the place of friendship in politics, by connecting theoretical questions to empirical answers.