The paper describes the interesting and widespread phenomenon of genealogic portraiture in Florence by analyzing the case of the Guadagni family and its series of portraits. The series was commissioned during the mid-Seventeenth century by senator Tommaso di Francesco and it was intended to decorate the family House behind the Nunziata thanks to the contributions of many artists. Both in terms of quantity and artistic quality, the Guadagni portrait series represents a precious testimony of this specific portraiture genre, which started during the middle of the sixteenth century and reached its climax during the following century. This genre saw its decline in the 1700s, when the aristocratic ancient families lost their importance, and their illustrious ancestors' portraits became simple relics of a remote past.