Summary — The problems posed by the crisis of the parliamentary state in Italy are considered in light of the political theories of Gaetano Mosca and the constitutional theories of Santi Romano, in particular in terms of their effect on the proposals for constitutional reform presented by the parties and unions between 1919 and 1921, and on the debate over constitutional legislation approved after the rise of Fascism. In particular, Gaetano Mosca’s intervention in the Senate and the subsequent response of Alfredo Rocco (minister for justice in the Fascist government), concerning the draft law on the prerogatives of the head of government (1925), brought out the fact that the parliamentary regime was subject to a Fascist-monarchist "diarchy" and that (according to Rocco) the monarchy had a statutary right of supreme power in judging whether the government was representing the "effective forces of the nation". The Statute continued to be the fundamental law of the State, in the context of which new laws concerning the Fascist regime were to be understood, in line with Santi Romano's public law doctrine that constitutional changes must maintain continuity with the previous constitution. The laws concerning "new political representation" (1928), the rules and functions of the Gran Consiglio (1928) the Camera dei Fasci e delle Corporazioni (1939), and the reform of the civil code (1940), were approved within the context of the Fascist-monarchist diarchy and on the assumption that the Statute was recognised as the fundamental law that defined and guaranteed the supreme political powers of the monarchy. The "royal" Senate, which was supposed to have been radically reformed, thanks to an "updating" of the Statute (which did not in fact take place), maintained its traditional nomination procedure and its legislative and constitutional role of "testimony" to the presence and the powers of the Crown. On 25 July, with the vote of the Gran Consiglio, the Italian political crisis was resolved "constitutionally", in terms of the Statute: the resignation of Mussolini and the King's nomination of the new Badoglio government fell within the sphere of the supreme political leadership of the monarchy, marking the end of the Fascist dictatorship and laying the foundations for the return to a parliamentary regime.