‘Is the Tacitean Tiberius largely and mainly the creation of the author?’ Modern readers of the Annals cannot know how the Tacitean Tiberius relates to the real Tiberius. Tacitus was writing a century after Tiberius came to power in AD 14, and in the ancient world, where the difficulties of communicating and transmitting information continue to be underestimated by today's scholars, the lapse of a significant period of time represented a formidable barrier to genuine knowledge of the past. Again, Tacitus wrote history according to contemporary conventions, which were very different from, and in many ways antithetical to, the principles taken for granted by modern historians. Finally, Tacitus was an exceptionally individualistic writer and his portrait of Tiberius gives every impression of being highly personalised, to the extent that some readers see Tacitus himself in his account of Tiberius. It is the Tacitean Tiberius with whom we are obliged to deal.

It is not to be doubted that Tacitus’ final view of Tiberius is presented in the obituary notice of the princeps which occupies the final paragraph of Book 6. Although numerous scholars have believed that the second part of the obituary, in which Tiberius’ mores are analysed, somehow conflicts with the narrative of Books 1–6, it is a priori unlikely that a writer of acknowledged brilliance lapsed into inconsistency at this final moment.

Whereas Augustus had single-mindedly eliminated all five of his rivals on his own route to power (1.2.1), he chose Tiberius as his successor only after the passage of almost three decades, during which his five preferred candidates had died prematurely (1.3.1–3); and, while Tiberius was then made ‘collega imperii’ and given the tribunician power, Augustus obliged him to adopt Germanicus (1.3.3–5; cf. 4.57.3) and, when Tiberius’ tribunician power was due for renewal, Augustus took the opportunity to apologise for Tiberius’ alleged shortcomings in front of the senate (1.10.7). It is perhaps not surprising that, when Augustus’ health began to fail and contemporaries speculated on the likely nature of a Tiberian principate, their predictions resulted in a paradox.