The popular BBC dramatization starring Derek Jacobi has renewed interest in Robert Graves' historical novels. Although entertaining and generally well-researched, Graves' depiction of Roman history is not universally accepted by historians and should be taken with a grain of salt. His characterizations of the various members of the Imperial Family, including the scurrilous portrait of Tiberius, are taken from "The 12 Caesars" of Suetonius, who had a number of political axes to grind.
The first novel, which chronicles the excesses of Augustus, Tiberius and Caligula, is decidedly the more entertaining of the two. As Claudius ruled moderately and intelligently, the second volume does little more than catalogue his accomplishments and Clau-Clau-Claudius becomes something of a b-b-bore. Curiously, the jacket blurb describes the books as an evocation of the "vitality, splendor and decadence of Imperial Rome at the beginning of the decline," although the Empire had yet to attain the splendor it would reach under the Antonines in the 2nd century AD.