The Roman imperial cult identified emperors and some members of their families with the divinely sanctioned authority (auctoritas) of the Roman State. Its framework was based on Roman and Greek precedents, and was formulated during the early Principate of Augustus. It was rapidly established throughout the Empire and its provinces, with marked local variations in its reception and expression. Augustus's reforms transformed Rome's Republican system of government to a de facto monarchy, couched in traditional Roman practices and Republican values. The princeps (emperor) was expected to balance the interests of the Roman military, Senate and people, and to maintain peace, security and prosperity throughout an ethnically diverse empire. The official offer of cultus to a living emperor acknowledged his office and rule as divinely approved and constitutional: his Principate should therefore demonstrate pious respect for traditional Republican deities and mores. A deceased emperor held worthy of the honor could be voted a state divinity (divus, plural divi) by the Senate and elevated as such in an act of apotheosis. The granting of apotheosis served religious, political and moral judgment on Imperial rulers and allowed living emperors to associate themselves with a well-regarded lineage of Imperial divi from which unpopular or unworthy predecessors were excluded. This proved a useful instrument to Vespasian in his establishment of the Flavian Imperial Dynasty following the death of Nero and civil war, and to Septimius in his consolidation of the Severan dynasty after the assassination of Commodus. The imperial cult was inseparable from that of Rome's official deities, whose cult was essential to Rome's survival and whose neglect was therefore treasonous. Traditional cult was a focus of Imperial revivalist legislation under Decius and Diocletian. It therefore became a focus of theological and political debate during the ascendancy of Christianity under Constantine I. The emperor Julian failed to reverse the declining support for Rome's official religious practices: Theodosius I adopted Christianity as Rome's state religion. Rome's traditional gods and imperial cult were officially abandoned. However, many of the rites, practices and status distinctions that characterized the cult to emperors were perpetuated in the theology and politics of the Christianized Empire. Background Roman For five centuries, the Roman Republic did not give worship to any historic figure, or any living man, although surrounded by divine and semi-divine monarchies. Rome's legendary kings had been its masters; with their removal, Republican Romans could identify Romulus, the founder of the