I, Claudius by Robert Graves

Into the 'autobiography' of Clau-Clau-Claudius, the pitiful stammerer who was destined to become Emperor in spite of himself, Graves packs the everlasting intrigues, the depravity, the bloody purges and mounting cruelty of the reigns of Augustus and Tiberius, soon to culminate in the deified insanity of Caligula.

I, Claudius and its sequel, Claudius the God, are among the most celebrated, as well the most gripping historical novels ever written.