I, Claudius, Claudius the God - Robert Graves

A grandson of Mark Antony, young Claudius is mistaken for a weakling and an idiot because of his stutter and his physical infirmities and grows up learning to use his reputation for harmlessness as a shield. Dismissed as insignificant by his powerful relatives as they compete with each other for power, he spends his time writing a secret history of the first three emperors of Rome as observed from his remarkable ringside vantage point―a dramatic tale that makes up the pages of I, Claudius. Claudius’s impersonation of a fool enables him to escape the intrigues and poisonings that mark his predecessors’ reigns, including the machinations of his murderous grandmother Livia and his dangerously mad nephew, Caligula. After assassinating Caligula, the Praetorian Guard declare Claudius the next emperor―over his protests. He accepts only to avoid civil war, and Claudius the God traces his attempts to strengthen Rome and restore the Republic. But his efforts are undermined by his corrupt wife, Messalina, and the ambitions of his own son, Britannicus, and he is unable to prevent the doom he foresees for Rome when his great-nephew Nero succeeds him as emperor.