The chapter addresses the complex interplay between the new roles of women and men and the diversity of family life courses (focusing on heterosexual individuals) in advanced societies, most specifically Europe and the US, from the 1960s, onwards. The multiple equilibria framework and the gender revolution theory serve as the point of departure. Considering labor market changes as the main drivers of family- and gender role changes, the chapter focuses on the development from the male breadwinner-female homemaker model to families with women as secondary earners, to dual-career families and more recently to the female primary earner or breadwinner-mother model, along with the slow and delayed transition of the male gender role from primary family provider to involved, caring men and the new father. The review demonstrates gender role changes being closely intertwined with the de-standardization of family biographies leading to a growing diversity of relationships over the life course as well as increasingly complex family compositions and household structures. Every stage of the family life course relates to a range of options, starting with partnership formation (cohabitation, marriage, LAT) if at all, through becoming a parent (when, how many times, in which family type, biological or stepparent) or not, to partnership dissolution (divorce / separation) and family reconstitution, shaping and shaped by altering gender roles. Diverse policy and cultural contexts (norms, values, attitudes, perceptions – and multi-ethnic families) facilitate or hinder family and gender-role transitions, impinging societal development.