Pontius Pilate probably came to be Prefect over Judea because of the influence of Sejanus. But who was Sejanus? While Casting Lots does not fully answer this question, Sejanus is both a major character in Casting Lots and an extremely interesting historical personage.
Sejanus’ tria nomina was Lucius Aelius Sejanus. Born into the equestrian class in 20 BC, Sejanus died on October 18, AD 31, at the height of his power and influence, having attained the Consulship.
Born to the powerful Seii clan, he was fortunate to be adopted by the prestigious and more powerful Aelian clan, which counted among its members two recent consuls and a military commander who had earned a triumph. In 2 BC, Sejanus’ adoptive father, Strabo, was appointed the prefect of the imperial bodyguard. Sejanus accompanied Gaius Caesar during his campaigns in Armenia in 1 BC. Then in 14 BC, Sejanus was appointed to the Praetorian Guard and served under his father. With his father’s appointment as Governor of Egypt in 15 BC, Sejanus became Prefect of the Praetorian Guard.
While the Praetorian Guard was established under Emperor Augustus, Sejanus refashioned it to be much more than the mere bodyguard to the Emperor. He transformed it into a powerful and influential branch of the government controlling public security, civil administration, and endowed with a veto over the acts of the Senate. He did this by centralizing the previously scattered nine cohorts of the Guard in one place just outside of Rome, by increasing the nine cohorts to 12, and by placing all of them under his sole command, rather than retaining the prior dual command system.
Sejanus also gained power by his influence over the Emperor Tiberius. In 22 AD, Tiberius began to share power with his son, Drusus. Because Tiberius was growing older, Sejanus hoped to establish himself as the heir apparent, even though Tiberius had a son. To establish himself as the heir apparent, Sejanus eliminated potential political opponents, including the emperor’s son, Drusus. Sejanus seduced Livilla, the wife of Drusus, and conspired with her to kill her husband. Livilla was able to poison her husband such that it appeared he had died of natural causes. So by 23 AD, Sejanus was called “Socius Laborum” (my partner in my toils) by Tiberius and appeared to be the heir apparent.
Sejanus thought the time was ripe for him to marry into the Emperor’s family. He divorced his wife in 23 AD. After waiting a discrete period of time, he then proposed to Tiberius in 25 AD that he marry Livilla. The emperor denied this request, warning Sejanus that he was in danger of overstepping his rank. (This episode appears in detail in Casting Lots.)
Sejanus changed his tactics and proceeded to isolate Tiberius. When Tiberius withdrew to the Isle of Capri in 26 AD, Sejanus was the de facto ruler of the empire. Sejanus’ star continued to rise until the death of Livilla in 29 AD. Her death affected Sejanus and made him undertake a program to remove all opposition. Spies and informers flew throughout Rome providing Sejanus with information which he used in trials against his opponents.
When Tiberius learned of Sejanus’ actions, Tiberius plotted a campaign to undermine Sejanus. He wrote letters to the Senate, some of which praised Sejanus and some of which denounced him. He resigned his consulship forcing Sejanus to do the same. Next, he conferred an honorary priesthood upon Caligula (who unfortunately was one of the few nobles who escaped Sejanus’ net). With these steps, support for Sejanus diminished. Then Tiberius appointed a new head of Praetorian Guard. Finally, Tiberius sent a letter to the Senate which summoned Sejanus to hear the letter read. Sejanus believed he was going to receive an honor. The letter began with a celebration of Sejanus. Then it abruptly changed to an order to arrest and imprison Sejanus. For a time the most influential and feared citizen of Rome, now amidst suspicions of conspiracy against Tiberius, Sejanus was executed, along with his followers.