The book explores the hitherto rarely discussed connection of magic with politics in the writings of Tacitus, Suetonius and Ammianus Marcellinus, offering insight into the way language of magic and ritual pollution is used as means of characterization and historiosophical commentary on the nature of power and political struggle. Religious deviation and innovation, theurgy, necromancy, black and erotic magic, the topoi of an emperor-magician, a semi-divine emperor-healer/saviour and a witch/poisoner, all play an important role in the analyzed texts. Magic is depicted as a way of abusing the official state religion; every such abuse disturbs pax deorum and brings misery on both the perpetrator and the whole state.