This presentation will begin with a discussion about child poverty and the SDGs: examining the prominence given the child poverty in the SDGs and how poverty in childhood undermines many SDG goal areas. One of key reasons for concern over poverty in childhood is precisely because it has lifelong consequences. The presentation will therefore move on to use a summation of the findings from the Young Lives cohort study to consider how poverty in childhood shapes children’s development and so later opportunities. The Young Lives study has followed cohorts of children growing up in Ethiopia, India, Peru and Vietnam since the Millennium and during a period of remarkable change. The study allows considerable potential to consider who was ‘left behind’ and why. The presentation will use the idea of the ‘development cascade’ to identify how factors at different points during the early life phase come together to shape skill development in mid adolescence and into early adulthood/ early adulthood, leaving children and young people with very different chances. The paper uses this framework to conclude by identifying key factors which can be shown to have particularly important consequences for children’s development, and so which merit particularly consideration for policy which seeks to improve children’s later opportunities.