Although Suetonius’ contemporary Tacitus may in the long run have acquired a loftier reputation, in the short run it was Suetonius who proved more influential. Indeed, after Tacitus we find no further serious historians writing in Latin until the solitary figure of Ammianus Marcellinus at the end of the fourth century ad. Historiography of the traditional sort was instead displaced by imperial biography, for which Suetonius provided the great model. In the early third century AD, at the same time as the Greek writer Dio Cassius was at work on his massive history of Rome, a man named Marius Maximus produced what was in effect a sequel to Suetonius’ work: the lives of twelve more Caesars, from Domitian's immediate successor Nerva (AD 96–8) down to M. Aurelius Antoninus, better known as Elagabalus (AD 218–22). This work itself has not survived, but references to it suggest that Maximus followed the Suetonian model fairly closely: in the use of a topical arrangement, the quotation of documents, and, of course, the inclusion of gossipy personal details. Ammianus had a dismissive attitude towards Marius Maximus and those who read his work: the degenerate nobles of his day, he complains (28. 4. 14), ‘hate learning like poison, and can be bothered to read only Juvenal and Marius Maximus’–two writers whom he links, we must suppose, because of their propensity for the lurid and sensational.
One of Ammianus’ contemporaries, however, apparently took a more tolerant view. This was the unknown author of the curious work known as the Augustan History, a collection of imperial biographies extending from Hadrian to Carinus and Numerian (ad 117–284). Although the individual biographies are presented as the products of various writers working in the late third and early fourth centuries ad, the collection as a whole is now regarded as the work of a single author active at the very end of the fourth century. His purpose in concocting this work, however, has been much debated, with some scholars suggesting that it was little more than an elaborate literary prank. Like both Suetonius and Marius Maximus, the author included scandal and gossip, and like them he often quoted generously from documents; unlike Suetonius, however, he seems to have invented the documents that he quoted. Also unlike Suetonius, he organized the material in his biographies chronologically, with only occasional and inconsistent use of a topical arrangement. But he nevertheless certainly presented himself as working within the Suetonian tradition. ‘As for me,’ he says, writing under the name Flavius Vopiscus, ‘it has been my purpose in treating of the life and times of emperors not to imitate the likes of Sallust, Livy, Tacitus, Trogus and other such eloquent writers, but Marius Maximus, Suetonius Tranquillus… and the rest, who have handed down to history this sort of material not so much with eloquence as with honesty’ (Augustan History,Probus 2.7).
At the same time, some people continued to appreciate Suetonius’ achievements from a more scholarly viewpoint. St Jerome mined On Illustrious Men for data to include in his Chronicle, a timeline of events from the creation of the world down to his own day; it is from Jerome's Chronicle, as I noted above, that we get most of our information about the lost portions of Suetonius’ work. Jerome also took it as the model for his own treatise On Illustrious Men; in the preface, he says that his friend Dexter had urged him to ‘follow Tranquillus’ and do for Christian men of letters what the earlier scholar had done for pagans. Yet it was not long after this that the works of Suetonius, along with those of many other classical Greek and Roman authors, began to disappear; the last western writer to quote from them is Isidore of Seville, in the early seventh century.
Apart from part of the section on grammatici and rhetors from On Illustrious Men, only The Twelve Caesars survived into the Middle Ages, and even it did not survive intact: the only manuscript available by the time of Charlemagne had lost its first few pages, which contained the preface and the beginning of the life of Julius Caesar. Although that manuscript itself no longer survives, it was the source of all later copies, which consequently also lack the opening sections of the work. The earliest extant manuscript dates to the early ninth century, a time when The Twelve Caesars enjoyed a certain vogue. The most striking evidence for this is the Life of Charlemagne by Einhard, which is clearly modelled on Suetonius’ life of Augustus. After the Carolingian period evidence forThe Twelve Caesars again becomes scarce: from the tenth century nothing survives, from the eleventh only three manuscripts, from the twelfth only two. But with the advent of humanism interest in Suetonius increased exponentially. The Twelve Caesars was one of Petrarch's favourite books; he owned two copies, one of which he commissioned himself, while his younger contemporary Boccaccio made extensive extracts in his own hand. By the fifteenth century, a copy of Suetonius had come to be regarded as an essential component of any learned man's library, to the point that over 100 manuscripts survive from this period.
By this time the popularity of The Twelve Caesars had begun to spread beyond the circles of those able to read the Latin original. The earliest translation into a vernacular language is a French version dating to 1381, and the first English translation appeared in 1606, the work of the great Elizabethan translator Philemon Holland. In the twentieth century the person most responsible for ongoing interest in Suetonius was the English poet and novelist Robert Graves, whose best–selling novels I, Claudius (1934) andClaudius the God (1935) drew extensively on The Twelve Caesars. Some twenty years later, when Graves was approaching the height of his career, he returned to Suetonius: his translation of The Twelve Caesars, first published by Penguin Classics in 1957, has become by far the most familiar and widely available English translation.