This chapter aims to study features and development of criminal law in the medieval and modern ages. The emergence, at the end of the eighteenth century, of the state monopoly on punishment, connected with the establishment of the statutory law as an ordering factor, represents a historical turn. Before, criminal law—much more than to the exercise of a right to punish—is related to the problem of determining justice in order to produce a public space substitute for revenge. The chapter, considering this different foundation, analyses the ordering factors structuring the criminal law system. It then focuses on peculiar features of the criminal trial and on key aspects such as the role of the judge, the sanctions regimes, the taxonomy of the crimes, and the regimes of proof. Some cursory remarks, as to how the criminal legal order turns into a system under a state monopoly, serve as a conclusion.