The essay deals with a crucial aspect of Italian juridical and institutional history, that is the relationship between the military and the civilian justice system. The article analyzes the Italian military penal codes issued in 1859 and 1869 in order to question the idea that the Italian military justice was exceptionally merciless, unconnected with criminal law, and disrespectful of the Constitution. The genesis of the military codes is reconstructed through parliamentary proceedings and final reports to the king in order to stress the fact that the military codes were part of a general reform of Italian criminal law in light of the 1848 Constitution principles. Simultaneously, the essay reconstructs the debate on military justice among both civilian jurists and officers in order to show the different attitudes towards the role of military justice in the disciplinary effort directed against the rank and file.