Many of his actions seemed resolutely pagan. Constantine founded a new city named after himself: Constantinople. Christian writers played up the idea that this was to be a 'new Rome', a fitting Christian capital for a newly Christian empire.
Indeed, when pagans blamed Christian impiety (meaning negligence of the old gods) for the barbarian sack of Rome in 410 AD, one of the foremost Christian intellectuals of the time, Augustine, Bishop of Hippo, regarded the charge as serious enough to warrant lengthy reply in his mammoth book 'The City of God'.
Constantine’s Influence on Christianity | Rome …
Christians were first, and horribly, targeted for persecution as a group by the emperor Nero in 64 AD. A colossal fire broke out at Rome, and destroyed much of the city. Rumours abounded that Nero himself was responsible. He certainly took advantage of the resulting devastation of the city, building a lavish private palace on part of the site of the fire.