<P> In 380, under Theodosius I, Nicene Christianity became the official state religion of the Roman Empire . Christian heretics as well as non-Christians were subject to exclusion from public life or persecution, though Rome's original religious hierarchy and many aspects of its ritual influenced Christian forms, and many pre-Christian beliefs and practices survived in Christian festivals and local traditions . </P> <P> The Western emperor Gratian refused the office of pontifex maximus, and against the protests of the senate, removed the altar of Victory from the senate house and began the disestablishment of the Vestals . Theodosius I briefly re-united the Empire: in 391 he officially adopted Nicene Christianity as the Imperial religion and ended official support for all other creeds and cults . He not only refused to restore Victory to the senate - house, but extinguished the Sacred fire of the Vestals and vacated their temple: the senatorial protest was expressed in a letter by Quintus Aurelius Symmachus to the Western and Eastern emperors . Ambrose, the influential Bishop of Milan and future saint, wrote urging the rejection of Symmachus's request for tolerance . Yet Theodosius accepted comparison with Hercules and Jupiter as a living divinity in the panegyric of Pacatus, and despite his active dismantling of Rome's traditional cults and priesthoods could commend his heirs to its overwhelmingly Hellenic senate in traditional Hellenic terms . He was the last emperor of both East and West . </P>

What was the role of religion in the roman empire at this time