In this book, McEvoy explodes the myth that the remarkable phenomenon of the late Roman child-emperor reflected mere dynastic sentiment or historical accident. Tracing the course of the frequently tumultuous, but nevertheless lengthy, reigns of young western emperors in the years AD 367-455, she looks at the way in which the sophistication of the Roman system made their accessions and survival possible. The book highlights how these reigns allowed for individual generals to dominate the Roman state and in what manner the crucial role of Christianity, together with the vested interests of various factions within the imperial elite, contributed to a transformation of the imperial image - enabling and facilitating the adaptation of existing imperial ideology to portray boys as young as six as viable rulers. It also analyses the struggles which ensued upon a child-emperor reaching adulthood and seeking to take up functions which had long been delegated during his childhood.

Through the phenomenon of child-emperor rule, McEvoy demonstrates the major changes taking place in the nature of the imperial office in late antiquity, which had significant long-term impacts upon the way the Roman state came to be ruled and, in turn, the nature of rulership in the early medieval and Byzantine worlds to follow.