But having arrived at this height, Sejanus’s head was turned, and he asked himself why he should exercise the rule and have all its burdens and dangers while he left to others the pomp, the honors, and the advantages.  Although Tiberius allowed the senate to heap honors upon his faithful prefect of the pretorians, and though he himself showed his gratitude to him in many ways, even going to the point of being willing to give him the widow of Nero in marriage, he never really expected to take him as his colleague or to designate him as his successor.  Tiberius was a Claudian, and that a knight without ancestry should be placed at the head of the Roman aristocracy was to him unthinkable; after the exile of Nero he had cast his eyes upon Caius, another son of Germanicus, as his possible successor.  Nor had he hidden his intention:  he had even clearly expressed it in different speeches to the senate.  Therefore Sejanus must finally have come to the conclusion that if he continued to defend Tiberius and his interests, he could no longer hope for anything from him, and might even compromise the influence and the popularity which he had already acquired.  Tiberius was hated and detested, there was a numerous party opposed to him in the senate, and he was extremely unpopular among the masses.  Many admired Sejanus through spiteful hatred of Tiberius, for it amounted to saying that they preferred to be governed by an obscure knight rather than by an old and detested Claudian who had shut himself up in Capri.

And thus Sejanus seems to have deluded himself into believing that if he succeeded in doing away with the emperor, he could easily take his position by setting aside the young son of Germanicus and profiting by the popularity which the fall of Tiberius would bring him.  Little by little he came to an understanding with the enemies of Tiberius and prepared a conspiracy for the final overthrow of the odious government of the son of Livia.  Many senators had agreed to this, and certainly few conspiracies were ever organized under more favorable auspices.  Tiberius was old, disgusted with everything and everybody, and alone in Capri; he had virtually not a single friend in Rome; what happened in the world he knew only through what Sejanus told him.  He was therefore entirely in the hands of the man who was preparing to sacrifice him to the tenacious hatred of the people and the senatorial aristocracy.  Young, energetic, and the favorite of fortune, Sejanus had with him a formidable party in the senate, he was the commander of the pretorian guard,—­that is, of the only military force stationed in Italy,—­and he had terrified with his implacable persecutions all those whom he had failed to win over through his promises or his favors.  Could the duel between this misanthropic old man and this vigorous, energetic, ruthless climber end in any other way than with the defeat of the former?

[Illustration:  Bust, supposed to be of Antonia—­daughter of Mark Antony and Octavia—­and mother of Germanicus.]