Family firms’ longevity is an understudied but highly relevant topic. Understanding the factors that drive family firms’ longevity is essential not only to improve the strategies of existing firms but also to inform investors’ decisions to support start-ups, taking on the responsibility of long-term allocation of resources. Hence, the purpose of this study is to advance available knowledge by examining relevant cases of bicentenary firms. Specifically, the research relies on a qualitative approach based on interviews. Several themes emerged from the analysis: the symbiotic relationship between the entrepreneur and the company (internal symbiosis) and between the company and its territory (external symbiosis) as one of the main causes of company longevity; longevity as a process; longevity as both a lever and a liability; the interplay between change and preservation.