EMPEROR

The Field of Swords

By Conn Iggulden

Delacorte. 466 pp. $25

THE SCOURGE OF GOD

A Novel of the Roman Empire

By William Dietrich

HarperCollins. 334 pp. $24.95

Historical novels suffer from a split personality -- are they history or are they novels? Can they be trusted to provide both entertainment and accuracy?

Alas, "Emperor: The Field of Swords," the third in a four-part series about Julius Caesar, offers neither. In his author's note, Conn Iggulden confesses that he has made one or two claims that may annoy historians. "If I have changed history in this book, I hope it has been deliberate rather than simple error. I have certainly tried to be as accurate as I could be."

What is one to make of this disclaimer when he is scrupulous about the properties of steel and iron but shows no hesitation about presenting the wildest inventions, such as that Brutus had an affair with Caesar's daughter Julia or that Brutus's mother, Servilia, was a madam with a string of bawdy houses?

Also, his dates bear no relation to reality. He adds at least 15 years to Octavian's age, which would make him in his mid-thirties when he was named Caesar's heir. But one of the most remarkable things about Octavian was the way the sheltered 18-year-old managed to outsmart his enemies and emerge at the top. All of this is negated if Octavian is a seasoned soldier and politician at the time.

On the entertainment front, the novel is plodding except when it attempts to spice things up with lively murders and kinky senator scenes. Most lacking of all is any psychological depth to Caesar. He appears motiveless and one-dimensional. We all know what he did, we would like to know why.

William Dietrich's "The Scourge of God" does well with both fact and fancy. It's a romance in the original meaning of the term: lots of adventure, swashbuckling, maidens in distress, magic swords and so on. Still, it manages to be surprisingly accurate in its depiction of the waning days of the Roman empire, the character of Attila and even some of the wildest events, which sound as if they were made up but are not. The sister of the Roman emperor of the West really did send a ring to Attila and ask him to rescue her, and he therefore claimed that she was proposing marriage and that half of Rome would be her dowry, which he could now make his mission to collect.

Dietrich is especially good at conveying elegiac images of the decline and emptiness of the countryside as Rome's power waned. "The baths were a ruin, the pools empty and the boilers unlit. The only water left running was through the abandoned community's sewage drains, and it was here that the hapless barbarians washed themselves and their clothes. . . . Still, they pretended at Romanness, preening in plundered clothing and living in half-ruined villas, like monkeys in a temple."

Dietrich also is adept at simplifying the byzantine politics of the times, a mixture of Byzantium itself, the Western empire, the Goths, Visigoths, Vandals and so on, sparing the reader from floundering about in this confusing sea.

Since, as Dietrich admits, little is known about the customs, rituals and habits of the Huns; he is free to invent these as he likes. We do not even know what Attila looked like, although we can assume he had a formidable physical presence. In a particularly vivid scene entirely of his own imagination, Dietrich has Attila wearing the cleaned-up bones of a recently executed victim as chain mail for horror effect. This is a fun and painless introduction to Attila and his world.