None of the explanations offered by our sources for the debate seems very credible. We need to start again, and think about the context in which these events took place. We need to imagine ourselves in Tiberius’ place to understand better what happened and why.

• What were the problems Tiberius faced as he walked into the senate?
• How else might he have responded to the problems?
• What did he want to get out of the debate?

Constitutional Issues

Augustus rose to power after a series of civil wars. He took magisterial powers in a series of settlements, in 28 and 27 BC, 23 BC, and 19 BC. Augustus was not king. In fact, there was no obvious name for what he was. We call him emperor which comes from the Latin imperator. In the Republic successful generals were acclaimed imperator by their troops. Under the Empire, only members of the imperial family were so acclaimed and so the title came be to associated with the ’emperor’. Sometimes ‘Caesar’ is used to designate the emperors, but Caesar was just the family name of Julius Caesar. Most common appears to have been the expression princeps or the term applied to a reign, principatus. These terms have the vague meaning of ‘leading citizen’ or ‘the period in which there was a leading citizen’. It follows that there was no strict definition of what an emperor was and thus it was very unclear how and to what Tiberius could accede.

There is another profound paradox at the heart of the situation. On his death, a summary account of the career of Augustus was published: The Res Gestae Divi Augusti (The Achievements of the deified Augustus). This was authored by Augustus and claimed in the penultimate chapter (34) to have restored the control over the state to the senate and people of Rome in 28 and 27 BC. After that point, his constitutional position was no greater than other magistrates. Augustus and Tiberius consistently represented themselves as living under a republic. This rules out inheriting power, which is what kings do. Consequently, imperial accession technically had to be ratified by law. We have the law for the accession of Vespasian, but such a law did not exist in AD 14.

Political Problems

As he sat in the senate, Tiberius needed to be sure of the loyalty of the key political constituencies. These included:

• The senators
• The people
• The soldier
• The generals

Of how many of these groups could be absolutely sure?

He also needed his regime to be seen as legitimate. If the regime was thought to be illegitimate, the soldiers might mutiny, the people riot, the generals march their troops, and the senators assassinate the new emperor. The most obvious sources of legitimacy were the political traditions of the Republic, the legacy of Augustus, and the authority of the senate.

In such circumstances, what else could Tiberius do but engineering a public display of loyalty from the senators and pose, as Augustus did so successfully, as a magistrate of the Republic. It is just that everyone knew it was a charade (which Tacitus exploits in his account) and his republican stance stored up trouble in his relations with the senate.