Tacitus, a Roman senator writing in the early second century, composed the Annals, a history of the emperors from Tiberius through Nero. This is Book 12 of that work. After a long gap in the surviving text, the story had returned to Claudius’s Rome: a learned emperor led by palace freedmen, his wife Messalina executed after a mock marriage, and Britain added to the empire.

Agrippina the Younger, Claudius’s niece, marries him and works to raise her son Nero. Nero is adopted; Britannicus, the son by blood, is pushed aside. Narcissus, the freedman who once ran the household, loses that fight and is killed. Seneca, a philosopher, and Burrus, commander of the emperor’s Guard, are set as tutors for the boy. Armenia stays a prize between Rome and Parthia. Claudius issues learned edicts; Agrippina issues the future. Rumor says mushrooms end the reign in 54. Claudius is made a god, and Agrippina becomes priestess of that cult, almost a co-ruler. This book is how a succession is built, and a teenager is handed an empire still warm.