Since no written account by the real Parmensis has survived, much of the ensuing tale is seen by us third—rather than second—hand, through the eyes of a reconstituted Parmensis as imagined by Stothard. It is reminiscent of the British poet-novelist Robert Graves’ excellent historical novel Count Belisarius. A less celebrated (and never dramatized) work than his masterpiece, I Claudius, Count Belisarius recounts the career of the eponymous hero, the Emperor Justinian’s greatest military commander, from the perspective of a fictionalized court eunuch, as imagined by Robert Graves. But, eunuch aside, there was nothing hermaphroditic about Graves’ book; it was written and marketed as a pure, unambiguous historical novel.

Not so The Last Assassin, which its publishers describe rather vaguely as “an epic turn of history.” Fact, fiction, or mélange, Stothard is very good at summoning up the spirit of the moment and inserting his own clever asides without breaking the mood. In the case of the assassination of Caesar—a chaotic affair that quickly degenerated into something akin to a feeding frenzy of sharks, with predators attacking each other as well as their common prey—Stothard tells us that,

…Parmensis had struck his own dagger blow but whether it was on the body of Caesar or one of his fellow killers he could not be sure. All that most witnesses remembered, as though the act were an hour ago, was the blood on so much fine linen, the streams of red on white, like the misty end of a drinking party, no not quite like that. What it was like then was nothing like what it became.

There’s obviously a lot more Stothard in that last line than there is Parmensis, but it admirably fits the occasion. The same is true of this vignette from Caesar’s funeral, where the real body, the “diminished corpse,” takes a back seat to a surreal object that “looked much more like Caesar’s body” than the body itself, an object,

…so vivid that it could only be a model, an effigy in wax which turned on a spit so that each of the twenty-three wounds could be seen by those who delivered them. From beneath this eerie machine boomed another list, the names of the killers, slowly, individually … The voice was of an actor, hired by mourners or fired by passion of his own…

PERHAPS THAT actor was a distant ancestor of one of those spooky bit players in Fellini films, although there is almost as much suggestive of Sergei Eisenstein as Frederico Fellini in the author’s description of the scene. With the burial of Caesar, and Mark Antony’s reading of his will—or what Mark Antony chose to reveal of the will, since he didn’t share the document with anyone at the time—events moved swiftly. Caesar was assassinated in 44 BC. By the end of the next year, the assassins—the gang that couldn’t stab straight—fled Rome, and Mark Antony, Octavian, and Lepidus (the “Second Triumvirate”) were firmly in control of Rome and most of Italy. Meanwhile, Rome’s greatest orator, Cicero, finally found himself in a jam he couldn’t talk his way out of. As Caesar’s nephew, named in his will as adopted son and heir, Octavian had a vested interest in not only punishing Caesar’s murderers but also using their pursuit as a credential—certification that he was ordained by fate to be Caesar’s avenging son and, by implication, legitimate heir to Caesar’s role as head of the empire. Octavian’s pursuit and killing of the assassins—like Stalin’s pursuit and killing of Trotsky—was at once a purging of foes and a way of establishing himself as the ordained successor of Caesar.

Octavian might have been willing to make an exception of Cicero, since the latter had long denounced Caesar’s ambition but not actively participated in the assassination plot. But Mark Antony had a personal score to settle with the silver-tongued solon who had once declared that if “you have a garden and a library, you have everything you need,” even while making a fortune as a defense attorney specializing in defending wealthy, corrupt clients and indulging an insatiable appetite for amassing treasure and real estate. Cicero, who seems to have found his oratory almost as intoxicating as his listeners did, had indulged in a series of vitriolic speeches targeting Mark Antony. They were called “Philippics,” drawing a parallel to the Greek orator Demosthenes’ famous denunciations of Philip of Macedon as a barbarian threat to the Athenian, rather than Roman, republic.

When it comes to political invective, resentment rather than imitation is the sincerest form of flattery. So deeply had Mark Antony resented Cicero’s barbs that, over Octavian’s mild objections, he ordered his pursuit and murder. Cicero tried to flee by sea, but he was not a good sailor and was so overcome by sea sickness that he had himself put ashore near his villa—one of many—at Formaiae. He seems to have had second thoughts the morning after, but they arrived too late. While being carried to the shore to re-embark he was overtaken by Mark Antony’s soldier-executioners. There, on a dusty road, according to Plutarch, “his person covered with dust, his beard and hair untrimmed, and his face worn with his troubles,” Cicero, finally at a loss for words, meekly yielded to his executioner. The head containing the silver tongue was severed from its body and delivered to Rome for public display along with Cicero’s right hand, presumably because it had been used to compose the offending speeches.

For his part, Octavian, while consolidating his own grip on power, never relented in his quest to bring Caesar’s actual assassins to what he considered justice. By the end of 42 BC, both lead assassins, Cassius and Brutus, had died by suicide after losing the dual Battles of Philippi to the joint forces of Mark Antony and Octavian. It is characteristic of the two victorious commanders that Mark Antony, a soldier’s soldier, was in the thick of the fighting while Octavian, feeling a bit under the weather, had viewed most of the action from the safety of a nearby swamp. Octavian ended up in charge of Rome and the heart of the empire while Mark Antony pursued dreams of eastern conquests that were consummated in Cleopatra’s boudoir rather than on the battlefields of Parthia.

By the end of 31 BC, Octavian, besides having dispatched most of Caesar’s assassins, had also disposed of his last serious rival for power, Mark Antony. At the rather farcical naval battle of Actium—in which the assassin Parmensis served—Mark Antony’s fleet was destroyed by Octavian’s technologically and tactically superior force. Octavian’s victory was made all the easier by the hasty departure of Cleopatra’s Egyptian fleet which was nominally allied to Mark Antony since his marriage to Cleopatra the previous year. Within another year, Cleopatra and Mark Antony had both committed suicide. Octavian, having formally annexed Egypt, was the undisputed ruler of an extended Roman Imperium.

THE LAST Assassin finishes where it began, with its title character experiencing uneasy night thoughts in his Athenian hideaway. As an epicurean,

In Athenian daylight he could remind himself that “death is nothing to me” … and that … “death brings neither pleasure nor pain.” In the darkness it was harder. At night, after the wind turned towards the sea and the scent of the flowers fell, he had begun to imagine a massive dark intruder disheveled and bearded, who would sever his head.

Parmensis’ primitive dream proved closer to the mark than his philosophical reflections for that was exactly how it ultimately came to pass: “Cassius Parmensis was the nineteenth and last assassin of Julius Caesar to die.” Octavian’s revenge was also Caesar’s. It turned out that the sickly eighteen-year-old nephew was a man with a plan and the single-minded determination to pursue it, doggedly and undistracted, while all around him seemingly braver, wiser, and cleverer men destroyed each other and themselves. Legitimacy was important to Octavian not only to secure his position as Caesar’s heir, but because his vision of Rome—similar but not identical to Caesar’s—hinged on reviving old Roman strengths and virtues. The restoration of duty, discipline, and devotion to ancestral values, and the grafting of them onto the citizens of a vast, multi-ethnic empire that had begun as a small, sturdy, and homogenous city-state, would occupy the man whom history now remembers as Caesar Augustus for the rest of a long, incredibly productive reign. It would also continue to give much to the world long after the golden age of the Pax Romana had been lost forever.

But as the great Augustan writer Livy noted, “Rome has so grown since its humble beginnings that it is now overwhelmed by its own greatness.” Perhaps the greatest of many Roman ironies is that Roman ideals—both republican and imperial—yielded their most impressive results when grafted onto sturdy stock elsewhere. The British Empire at its height was very much an Augustan venture, and our own founding fathers were inspired by many chapters from Roman history, not least the example of a Roman soldier patriot who saved the early republic, turned his back on power, and then returned to the shade of his own fig tree. His name was Cincinnatus and, when George Washington voluntarily retired after serving two terms as our first president, his grateful countrymen hailed him as the “American Cincinnatus.”