Upon the death of Augustus, Tiberius Claudius Nero stood as the last logical choice in a long and tumultuous line of potential heirs. In 14 AD, at the age of 56, Tiberius ascended to Imperial power as a somewhat uncertain figure. The continuation and success of the newly created Principate rested squarely on the shoulders of a man who seemingly had only a partial interest in his own personal participation.
For the first time the transfer of power from the greatness of Augustus was to be tested. The passing of this test would prove to be more a culmination of Augustus' long reign and establishment of precedent than the ability of Tiberius to fill the enormous sandals of his step-father.
While Augustus was the perfect political tactician with powerful personality yet approachable demeanor, Tiberius was a direct contrast. He was a dark figure, keenly intelligent, sometimes terribly cunning and ruthless, yet pre-disposed to a more Republican ideal than any emperor that followed him. Tiberius' failures, however seem to have been his inability to define his own role within the Principate and the roles of those around him, including the Senate. While he professed a desire for the Senate to play a more active role in Imperial government, he did little to illustrate what these roles should be. To an aristocratic body that had been cowed into general subservience through the sheer will and force of Augustus, defining a new role required more definitive action than the simple desire of Tiberius for change.
He was inconsistent in policy and behavior, sometimes dictating his own idea of order from the position of ultimate power, sometimes withdrawing completely in favor of any who might dictate the appearance of command. Mood swings and depression plagued him, perhaps resulting from a life spent as an uncertain member of the 'Julio-Claudian' family. Until his final ascension, and only after the deaths of several favored 'heirs', did Tiberius probably know for sure that the ultimate power would actually belong to him. His own withdrawal from public life in the midst of Augustus' search for permanent familial hierarchy (12 BC - 2 AD), certainly indicates a detachment from desire for ultimate power. His second withdrawal from public life, later in his actual reign, would prove to be the ultimate undoing of his own legacy. His susceptibility to the scheming of those around him, while possibly hoping for someone to emerge to allow his own escape, made Tiberius, and Rome itself, vulnerable to tyranny and uncertainty.
From the very beginning of his reign, Tiberius was shrouded with uncertainty. When the Senate convened to confirm him, the procedure was completely unknown. Augustus had assumed power over a period of years through a systematic assembling of various Republican powers, while Tiberius was to be handed the entire thing, all at once, on a platter. Like Augustus' before him, he seemingly made an attempt to refuse the ultimate power of the state, instead preferring a more limited role. But his desires were apparently unclear, and the Senate too was certainly unsure of what action to take. After some consternation, Tiberius eventually accepted the highest order of power. Still, Tiberius left evidence of his own desire to be rid of the mantle of authority, being the only emperor to refuse the title 'Pater Patriae' (father of the country).
Tiberius' behavior in governing matters, especially in interaction with the Senate was confusing at best. Despite efforts to get them to return to at least a semblance of Republican rule, his view of them, 'men fit to be slaves' coupled with his own liberal use of the treason laws, certainly left the Senate frightened and confused. This relationship would never improve, and in fact would worsen, thanks to the rise of men like Sejanus. Tiberius' would be blasted by later Roman historians, all of whom would have ties to the Senatorial elite, and therefore, despite a generally solid rule (especially in terms of provincial administration), his legacy was permanently stained. However, Tiberius was faced with more trouble than that caused by political uncertainty between he and the Senate.