Based on a corpus which consists of 150 family books written between 1260 and 1480, this study intends to define the representations that Florence citizens had of their republic, of its running and of their role within it.The first part aims at identifying which room is given to historical and political passages in these books, and the functions of these excerpts in the overall writing strategy. The point is to study how the building of family identity was connected to the life of the city.The second part contains a stylistic and semantic analysis of the narrative parts that are dedicated to the major events of the 14th and 15th centuries. It offers a series of snapshots that define several specific configurations of the city’s political body and of how families refer to it. This textual analysis also provides us an image of the Florentine intellectual framework and a list of the key-concepts that characterized the political thought of the authors – which goes far beyond a mere interest in chronicles. The third part focuses on the use of those keywords in a diachronic perspective, in order to identify the evolutions, the involutions and the breaking points of this thought over the generations, and questions the link between citizens’ active political participation and their private writing on city affairs. The appendix presents transcriptions of the excerpts on the life of the city contained in the unpublished family books of the Florentine families, as well as biographical notes on their often unknown authors.