praetorian influence over the Imperial house, the Senate and through it, the state. In 31 AD, his praetorian prefect Sejanus – by now a virtual co-ruler – was implicated in the death of Tiberius' son and heir apparent Drusus, and was executed as a public enemy. In Umbria, the imperial cult priest (sevir Augustalis) memorialised "the providence of Tiberius Caesar Augustus, born for the eternity of the Roman name, upon the removal of that most pernicious enemy of the Roman people". In Crete, thanks were given to "the numen and foresight of Tiberius Caesar Augustus and the Senate" in foiling the conspiracy, but at his death the Senate and his heir Caligula chose not to officially deify him. Caligula's rule exposed the legal and moral contradictions of the Augustan "Republic". To legalise his succession, the Senate was compelled to constitutionally define his role, but the rites and sacrifices to the living genius of the emperor already acknowledged his constitutionally unlimited powers. The princeps played the role of primus inter pares only through personal self-restraint and decorum. It became evident that Caligula had little of either. He seems to have taken the cult of his own genius very seriously, and is said to have enjoyed acting the god – or rather, several of them. However, his infamous and oft-cited impersonations of major deities may represent no more than his priesthood of their cults, a desire to shock and a penchant for triumphal dress or simply mental illness. Whatever his plans, there is no evidence for his official cult as a living divus in Rome or his replacement of state gods, and none for major deviations or innovations in his provincial cult. His reported sexual relations with his sister Drusilla and her deification after death aroused scorn from later historians; after Caligula's death, her cult was simply allowed to fade. His reported extortion of priesthood fees from unwilling senators are marks of private cult and personal humiliations among the elite. Caligula's fatal offense was to willfully "insult or offend everyone who mattered", including the senior military officers who assassinated him. The histories of his reign highlight his wayward impiety. Perhaps not only his: in 40 AD the Senate decreed that the "emperor should sit on a high platform even in the very Senate house". Claudius (his successor and uncle) intervened to limit the damage to the imperial house and those who had