The notion that a “developmental difficulty” underlies the appearance of clinical symptoms has become a time-honored tradition in family therapy just as it has been in individual therapy. Yet, unlike the well-established and well-researched models of child and adult development, those in family development are rudimentary. This volume gathers some of the most prominent family theorists, researchers, and clinicians to elucidate the specific dimensions and processes of spontaneous and therapeutically induced change over the family life cycle. The book introduces new conceptual models that integrate the temporality of the life cycle approach with systems theory. By their very nature, these models cut across therapeutic orientations and have important clinical applications.