The essay introduces the monographic section on Institutions, Relations and Political Cultures in the cities between the State of the Church and the Kingdom of Naples (1350-1500). After focusing on two persistent keys to the urban political history of the late Middle Ages of Italy – the dualistic and the plural one based on the regional states – there are some ideas for reflection starting from the historiographic acquisitions of the last two decades. We then illustrate the new perspectives within which it is intended to verify, through the collected essays, the existence of an area of urban political culture around the borders between the state of the Church and the kingdom of Naples, and the questionnaire within which the authors of the individual essays were moved.