“Those who think to do away with petitions would overthrow the entire system of the State”. This remark – taken from an anonymous eighteenth-century account of the political organization of the Duchy of Parma and Piacenza – describes well the importance attributed to complaints in the organization of the state. Through complaints, or petitions, it is generally possible to verify a number of fundamental forms and modes of communication between society and the institutions of the ancien regime, and to reconstruct the procedures of mediation, repression, acceptance, and agreement adopted by princes, sovereigns, or magistracies in response to social demands.