International law scholarship has traditionally been understood in Italy as encompassing the study of both public and private international law. The two subjects are still considered jointly for recruitment purposes and are mostly taught by the same professors. Pasquale Stanislao Mancini, who regarded nationality as a foundation of both disciplines, had a major influence on the popularization of this approach in the mid-nineteenth century. The advent of positivism, a few decades later, entailed a general rejection of Mancini’s views but did not challenge the integrated approach to the different branches of international law. Rather, the positivist turns triggered a renewed reflection on the ties between the two subjects. The study of international law, some argued, should cover, alongside international rules, such municipal rules as deal with international matters. The chapter outlines the origin and evolution of the Italian integrated approach to international law and its perception by today’s scholars, in Italy and abroad.