Another fictionalized biography from British veteran Massie of an ancient great (Let the Emperor Speak, 1987, etc.)--though, here, the Roman emperor Tiberius sounds more like a US president complaining about Congress than an imperial swashbuckler. In the purported-to-be real memoirs of Tiberius--given to Massie by a mysterious Italian count--Tiberius, a stiff-necked prig, describes his gradual and reluctant rise to power, with accompanying nuggets of obvious political sagacity thrown in to enhance his already sizable gravitas. As his mother, Livia, tells him when he is forced by his imperial stepfather Augustus to marry the imperial daughter, free-spirited Julia: ``People like us cannot live by private impulses for we cannot live private lives.'' Livia, an astute politician and even more adroit survivor, has spent her life helping her husband and advancing Tiberius through the treacherous shoals of Roman politics, where wives, cousins, and closest friends murder and betray with the same diligence that they pursue pleasures equally as sordid. Tiberius, a man who keeps his counsel, successfully fights the Germans, but then--tired of fighting, his marriage disintegrating, and dismayed that the Republic is turning into a despotism--he retires to Rhodes for four years. This tendency of his to cut and run from anything unpleasant will be repeated. He doesn't intervene when estranged wife Julia's scandalous behavior leads to her exile on a remote island; doesn't fight the machinations of his niece Agrippina; and, when he does become Emperor, despairs of reforming the Romans and heads for Capri, where he signs imperial documents but otherwise reads and thinks. Which, of course, means that there are lots of plots and counterplots, plus friends who betray and must be punished. Poor Tiberius, as Livia observes, was always ``a bad judge of character.'' Not as scurrilous as Suetonius or as lively as Graves. More a sententious plod.