This chapter analyses the different ways in which child development and related concepts – such as autonomy, capacity, and agency – have been understood and interpreted in child law scholarship during the last century. The chapter begins in the nineteenth century, at a time when the legal conception of ‘the child’ in the Western world was changing, and the law, as a social agent, began to embrace new positionalities of children in society. The view that children are the property of their fathers was replaced by romantic middle-class ideas of children as a source of pleasure and joy for their parents. Legal measures that reflected political interests in children’s lives and futures were introduced, particularly in the realm of welfare, education and health.1