Prior research lacks an understanding of how decision makers preserve longevity within family businesses. This study examines longevity under a microfoundational lens, through an interpretive qualitative research design. The selected cases are nine long-established Australian family wineries. The outcome is a multilevel grounded model of the preservation of family firm longevity that integrates the dual firm-family relationship with the individual level of decision makers. The model shows the role played by interactions among multiple levels of analysis — namely, the individual, the family and the firm — in preserving the longevity of the family business.