The works of Ambrosiaster, a Christian writing in Rome in the late fourth century, were influential on his near contemporaries and throughout the Middle Ages. In the first half of her study, Sophie Lunn-Rockliffe addresses the problem of the author's mysterious identity (which scholars have puzzled over for centuries) and places him in a broad historical and intellectual context. In the second half she addresses Ambrosiaster's political theology, an idea which has been explored in other late Roman Christian writers but which has never been addressed in his works. She looks at how Ambrosiaster's attitudes to social and political order were formed on the basis of theological concepts and the interpretation of scripture, and shows that he espoused a rigid hierarchical and monarchical organization in the church, society, and the Roman empire. He also traced close connections between the Devil, characterized as a rebel against God, and the earthly tyrants and usurpers who followed his example.