Also the title of a thirteen-part miniseries adapted from Graves' two books, produced by the BBC and originally televised on PBS' Masterpiece Theater in 1977.
Many consider this to be the single greatest work of entertainment ever shown on TV (at least until the advent of The Wire on HBO) helping to add to the lustre of many British actors, including:
Derek Jacobi - Claudius
John Hurt - Caligula
Sian Phillips - Livia
Brian Blessed - Augustus
Patrick Stewart - Sejanus
George Baker - Tiberius
Margaret Tyzack - Antonia
Patricia Quinn - Livilla
Full of sex, violence, royalty, (not entirely accurate) political intrigue, wonderful set design and costumes, the miniseries stirred quite an interest in the history of the Roman Empire when initially televised.
A little known fact: Patricia Quinn also played Magenta in The Rocky Horror Picture Show.