We draw insights from the perspective of theory of complex adaptive systems to gain knowledge about complex interactions and the dynamic nature of entrepreneurial family business groups. We develop a theoretical understanding of complex longevity in entrepreneurial family firms through a detailed analysis of a multigenerational family business group. We propose that family business groups are the outcome of complex temporal dynamic interactions within and between family business subsystems: family, business and ownership. Our analysis shows that even complex systems may have a subtle balance inherent in the interaction of their subsystems. A family can control the complexity of a family business group by understanding and appropriately managing the complexity inherent as a family, as a business group and in ownership ties across the family and the businesses.