This article presents a survey of research on childhood in antiquity and describes briefly the position of children in late antiquity and early Christianity. Special attention is given to the relationship between childhood and gender, with a focus on boyhood. The article analyses the apocryphal Infancy Gospel of Thomas, which tells the childhood story of Jesus from age five to twelve. This brief story, which consists of miracle stories and discourses, originated in Greek in the 2nd century CE and became widely popular. The article shows that its depiction of Jesus conforms to current ideas of gender, gender relations, and gender socialisation. A central claim in the article is that boys were not expected to show the same degree of self-restraint as were adult males, but that as children they were allowed to behave more emotionally and unpredictably. Rather than being literarily inferior or theologically aberrant, the Infancy of Gospel of Thomas in its depiction of Jesus gives a lively and credible glimpse into the world and development of a late antiquity or early Christianity male child on his way from boyhood to male adult life.