This paper reads Foucault’s 1975-6 lecture series Society Must Be Defended. It argues that the notion of counter-history developed in these lectures depends on a particular construction of Rome, as that which counter-history counters. Foucault’s version of Rome in turn depends on a surprisingly conventional reading of two monumental histories (Livy’s Ab Urbe Condita and Virgil’s Aeneid) as ‘the praise of Rome’. Reading Foucault’s work instead with Lucan’s Pharsalia renders visible a counter-history within Rome itself. This reading demonstrates the ways in which reception theory can usefully illuminate and supplement Foucauldian genealogy as a critical-historical method.