This document synthesizes knowledge about opportunities to improve the state of early child development (ECD) on a global scale. In keeping with international policy standards, we define early childhood development as the period from prenatal development to eight years of age. What children experience during the early years sets a critical foundation for their entire lifecourse. This is because ECD &em; including the physical, social/emotional and language/cognitive domains &em; strongly influences basic learning, school success, economic participation, social citizenry, and health. Within the work of the Commission, ECD has strong links to other social determinants of health, particularly Urban Settings, Gender, Globalization, and Health Systems. Areas of common concern with these determinants are discussed throughout this document. Research confirms a strong association between child survival and child development, such that child survival and health agendas are indivisible from ECD. Our developmental approach to the early years includes the factors that affect child health and survival, but goes beyond these to consider how the early years can be used to create thriving global citizens. Here, we provide a framework for understanding the environments (and their characteristics) that play a significant role in influencing early development. The evidence and its interpretation is derived primarily from three sources: 1) peer-reviewed scientific literature, 2) reports from governments, international agencies, and civil society groups, and 3) a Knowledge Network of experts in ECD that is representative in both international and inter-sectoral terms. The principal strategic insight of this document is that the nurturant qualities of the environments where children grow up, live and learn &em; parents, caregivers, family and community &em; will have the most significant impact on their development. In most situations, parents and caregivers cannot provide strong nurturant environments without help from local, regional, national, and international agencies. We propose ways in which governments and civil society actors, from local to international, can work in concert with families to provide equitable access to strong nurturant environments for all children globally.