This book offers the first extensive investigation of Italian crime fiction in the period between 1861, the year of Italy's unification, and 1941, when the famous Mondadori series 'I libri gialli', which had published crime novels since 1929, was suppressed by the fascist regime. By exploring the formal and thematic metamorphoses of Italian crime narratives and probing the different socio-political roles that they played in both the liberal and fascist periods, it provides a radical re-conceptualization, in both historical and theoretical terms, of a form of fiction that has been largely marginalized for both aesthetic and ideological reasons, uncovering how it was implicated in the construction of the modern state and in the articulation and shaping of the process of 'making Italians'.