The Fall of Sejanus (October 18, AD 31)

On October 18, AD 31, the Senate in Rome heard a long letter from Tiberius on Capri. The letter first praised Sejanus and then accused him of treason. Senators drew away from him. The Guard, secretly handed over to a new commander, arrested the prefect. Soon after he was put to death, followed by his relatives and supporters.

The course of events is certain; Cassius Dio describes it. The day is sometimes given as October 16, and Tacitus (Annals 6.25) mentions October 17. Most often October 18 is accepted. Sejanus’s aims are disputed. Tacitus speaks of a drive for power. Some scholars see a plan for a regency over the emperor’s grandsons.