Using longitudinal data, this chapter studies the development of educational inequalities over the life course in 12–17 different industrialized societies. By comparing highly-standardized country case studies in specific phases of the educational career, it provides evidence of major communalities in modern societies. First, the cross-national findings show that educational inequalities are created and perpetuated in family settings, early in a child’s life, long before children start school. Children from less privileged families are the ones who are least likely to attend high-quality institutions, and if they do, their gains are only moderate and generally too small to effectively counteract the family influence. When children are in school, the comparative analyses demonstrate that socioeconomically-advantaged families manage to secure the “pole positions” in education for their children, regardless of the organizational specificities of the school system across different countries. They always succeed in strategically exploiting various opportunities provided by different school systems. Finally, the cross-national comparisons of adult learning over the life course show a strong cumulative advantage: Adult learning tends to reproduce and reinforce the outcomes of initial formal education in the later adult life course.