Tiberius as emperor: his accession and relations with the Senate, the use of treason (maiestas) trials, the rise and fall of Sejanus and the retreat to Capri, and the problems of judging Tiberius given the hostility of Tacitus and Suetonius.

What this dot point is asking

The period study turns to Tiberius (reigned AD 14 to 37), Augustus's successor, and the strains that appeared once the principate passed to a second man. This page covers his accession and difficult relations with the Senate, the growth of treason (maiestas) trials, the rise and fall of Sejanus and the retreat to Capri, and the problem of judging Tiberius when the main sources, Tacitus and Suetonius, are hostile. The topic rewards a ranked analysis of why his reign soured and a careful handling of a biased tradition.

The answer

Accession and relations with the Senate

The accession set the tone: Tiberius's awkwardness, real or affected, created a gulf between emperor and Senate that the rest of the reign widened.

The treason trials

The treason trials are usually judged the deepest cause of the breakdown between Tiberius and the Senate: they turned the principate's relationship with the elite into one of fear.

The rise and fall of Sejanus

The dominant figure of the later reign was Sejanus, the praetorian prefect. He concentrated the scattered praetorian cohorts in a single camp in Rome, won Tiberius's complete trust, removed rivals (including members of the imperial family thought to stand in his way), and effectively ran the state, the more so after Tiberius withdrew to Capri from AD 26. His power seemed unassailable until, in AD 31, Tiberius abruptly turned on him: Sejanus was denounced in a letter read to the Senate, arrested and executed the same day, and a bloody purge of his supporters followed.

The Sejanus affair reveals two things the period study stresses:

• The danger of the praetorian prefecture, the command of the troops nearest the emperor.
• The insecurity at the heart of the principate, where a trusted servant could nearly seize control and an emperor could destroy him overnight.

Examples in context

A model answer ranks the causes and treats Tacitus's portrait as a construction to be evaluated, not a transcript.

Try this

Q1. Assess the significance of Sejanus in the reign of Tiberius. [20 marks, period essay style]

• What the marker wants. An AO1 and AO2 argument that Sejanus concentrated the praetorians, dominated the state in Tiberius's absence, and revealed the danger of the prefecture and the insecurity of the principate, weighed against other features of the reign, with a judgement and source evaluation.

Q2. What office did Sejanus hold, and where did he concentrate its troops? [2 marks]

• Cue. He was praetorian prefect, and he concentrated the previously scattered praetorian cohorts in a single camp in Rome, greatly increasing his power.