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 compulsion 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 conspired against it, and had Caligula's public statues discreetly removed.