This paper examines the relation between three concepts: a child’s will, children’s agency and child labour. Addressing the current debate about children’s agency, this paper shows how these concepts were developed in Byzantine society in order to advance a religious agenda that encouraged the child to run away from home in favour of a new life in a monastery. Children were attributed with a will of their own and acted upon it before they reached the age of puberty. This perspective took the child out of the private sphere by attributing agency to it. The paper addresses the current debate about children’s agency revealing the conceptualization of this term as motivated by an economic agenda in which the need to profit from the child’s labour plays an important role.