This book is about the importance of the couple relationship in the broadest terms. It draws on clinical researches into the inner lived world of adult couples, empirical developmental research into children and parenting, as well as the legal setting when relationships break down. It bridges the inner and outer worlds, showing how our most intimate relationships have vital importance at all levels, from the individual and the family, to the social setting and explores the implications for practice and policy. Above all, it is a book about applications of clinical thinking linked with research knowledge, as tools for front line workers and policy makers alike. It draws on the tradition of applied clinical thinking and research of the Tavistock Centre for Couple Relationships, linking current thinking with the history of ideas in each area it covers, as well as considering implications for the future.