The Romans inherited Greek historiography as they inherited other elements of Greek culture, aware of its prestige and emulating it in some ways but inevitably giving it the imprint of their quite different temperament. Fittingly, it was a Greek writing in Greek, Polybius (c. 200–c. 118 bce), who first offered key insights into the development of the Roman state and discussed aspects of Roman society that the Romans themselves had hardly noticed. He asked: “Can anyone be so indifferent or idle as not to care to know by what means, and under what kind of polity, almost the whole inhabited world was conquered and brought under the domination of the single city of Rome, and that too within a period of not quite 53 years?” In answering this question, Polybius drew comparisons between the Romans and the Greeks, the latter of whom failed to forge a lasting empire, even under Alexander the Great (356–323 bce). The primary reason for Rome’s success, according to Polybius, was the Roman character, as reflected in statesmanship, public spirit, and moderation toward defeated peoples.
Polybius also argued that Roman political institutions were superior to Greek ones. He accepted the theory of the cyclical degeneration and regeneration of Greek city-states, which had been elaborated by Aristotle. This theory maintained that city-states develop first as despotisms and evolve through periods of monarchy, tyranny, aristocracy, oligarchy, democracy and finally mob rule before the restoration of order in a new despotism. There was, however, nothing inevitable about this cycle, and Polybius at one time believed that the Romans might avert it because the constitution of the Roman Republic was mixed, allowing for some monarchical and some popular elements as well as the aristocracy of the Senate. (This theory of the benefits of mixed government was to have a long career.) Finally, Polybius believed the Romans had been favoured by Tyche (“fate” or “fortune”), which was partly responsible for drawing the world under Roman rule.
Like Thucydides, Polybius relied on personal experience and the cross-examination of eyewitnesses. Thus, he retraced the route of the Carthaginian general Hannibal across the Alps and observed the siege of Carthage in 146 bce. Although he scorned historians who merely sat in their studies, he also condemned petty histories of small corners of the world. To the contrary, the triumph of Rome called for a universal history: “Up to this time the world’s history had been, so to speak, a series of disconnected transactions.…But from this time forth History becomes a connected whole: the affairs of Italy and Libya are involved with those of Asia and Greece, and the tendency of all is to unity.” Diodorus, Sallust, and Livy
Unfortunately, a method based on personal experience and eyewitness accounts could capture a moment of decisive conquest but could not yield universal history. It remained for Diodorus Siculus in the 1st century bce to come closest, among ancient writers, to this ideal. Diodorus traced to 60 bce the histories of Arabs, Assyrians, Egyptians, Ethiopians, Greeks, Indians, Romans, and Scythians—not to mention Amazons and the residents of Atlantis. He is one of the main ancient supporters of the claim that Plato and other Greek thinkers learned their wisdom from the Egyptians.
Less than a century after Polybius explained the rise of the Roman state, Roman historians were beginning to speak of its decline. Sallust (c. 86–c. 35/34 bce) described the conspiracy of the Roman patrician Catiline in the Bellum Catilinae (43–42 bce; Catiline’s War), and his Bellum Jugurthinum (41–40 bce; The Jugurthine War) focused on the war against Jugurtha, the king of Numida (roughly present-day Algeria). The lesson of both was that the republic was rotting inwardly through corruption and the arrogance of power. Indeed, in Sallust’s systematic analysis Rome was shown to be suffering the general fate of empires.
Livy (59/64 bce–17 ce), one of the greatest Roman historians, lived through the fall of the republic and the establishment of the principate by Augustus, the first Roman emperor. Like Sallust, Livy was inclined to idealize the severe virtues of republican Rome. His monumental history, most of which has not survived, starts with the founding of the city and extends into the rule of Augustus. Like the Aeneid, by the Roman poet Virgil, Livy’s work served to memorialize Rome’s early history just as the republic was being transformed into an empire. Tacitus
Nobody was more aware of this development, or decline, than Tacitus (56–120). His two great works—the Annals, which covers the years 14–68 ce, and the Histories, which begins with the famous “year of the four emperors” (69 ce) and ends with the death of the emperor Domitian (96)—provide an important account of the first century of the principate. Tacitus was a self-conscious stylist, and in his treatise on style he claimed that styles were themselves the product of historical changes rather than being entirely the decision of the historian. His own writing is perhaps most remarkable for his concise epigrams. Of the short-lived reign of the emperor Galba, for example, Tacitus wrote: “Capax imperium, nisi imperasset” (“He would have been capable of ruling, except that he ruled”). And concerning Roman methods of pacification, he observed, “Solitudinem faciunt, pacem appelant” (“They have made a desert and call it peace”).
Politics, as it had been known in the republic, no longer existed; the intrigues of the imperial family and of its bodyguard, the Praetorian Guard, determined the fate of Rome. Instead of creating a master narrative about the impersonal forces that might have led to this development, as Polybius or even Sallust might have done, Tacitus focused on the character of the various emperors. As was typical of ancient authors, he had no conception of character as developing through the course of a lifetime. Innate character, however, reveals itself fully only in crises, or when the possession of absolute power allows all its latent features to emerge—as with the vanity and cruelty of Nero. Tacitus’s emphasis upon character, despite the crudity of his psychological theories, made him a pioneer of psychohistory. It also brought the form of historical works close to that of multiple biographies. Suetonius and Plutarch
This is even more true of the De vita Caesarum (Lives of the Caesars), written by Suetonius in the 2nd century. His treatments consist of an account of each emperor’s administrative and military accomplishments followed by a description of his character and personal life. Although Suetonius, a former imperial secretary, drew upon the imperial archives in composing his Lives, the work is best known for the scandalous details it provides regarding the private lives of the emperors. In this he differed from the best-known of the ancient biographers, Plutarch, whose Bioi paralloi (Parallel Lives) juxtaposed the life stories of 24 Romans and 24 Greeks who had faced similar experiences. His purpose was to draw moral lessons from the lives of these figures. If they responded differently to their challenges, it was partly a consequence of character, but weaknesses of character could—and should—be overcome by a strenuous exercise of virtue.