Renewal of persecution under Gratian
Upon the death of his father (Valentinian I) in the year 375, Gratian began his actual reign at the age of sixteen. Six days after the death of Valentinian I, Gratian's half brother, Valentinian II, who was only four years old, was also declared emperor. After the death of Valens, at the battle of Adrianople in 378, Gratian chose a Spaniard named Theodosius I to succeed his uncle. Gratian had been educated by Ausonius who had praised his pupil for his tolerance. Upon the death of his father, Gratian came under the influence of Ambrose, who became his chief advisor. Under the influence of Ambrose, active steps to repress Paganism were taken.
The influence of Ambrose was a significant force that brought to an end a period of widespread, if unofficial, religious tolerance that had existed since the time of Julian. Gratian dealt Paganism several blows in 382. In this year, Gratian appropriated the income of the Pagan priests and Vestal Virgins, confiscated the personal possessions of the priestly colleges and ordered the removal of the Altar of Victory. The colleges of Pagan priests also lost all their privileges and immunities. Gratian declared that all of the Pagan temples and shrines were to be confiscated by the government and that their revenues were to be joined to the property of the royal treasury.
Pagan Senators responded by sending an appeal to Gratian, reminding him that he was still the Pontifex Maximus and that it was his duty to see that the Pagan rites were properly performed. They appealed to Gratian to restore the altar of Victory and the rights and privileges of the Vestal Virgins and priestly colleges. Gratian, at the urging of Ambrose, did not grant an audience to the Pagan Senators. In response to being reminded by the Pagans that he was still the head of the ancestral religion, Gratian renounced the title and office of Pontifex Maximus under the influence of Ambrose, declaring that it was unsuitable for a Christian to hold this office.