The tables are turned: Christians persecute Pagans after 313 CE:

The waves of persecutions by the Roman Empire against Christians ended in 313 CE when Constantine I (306–337 CE) published the Edict of Milan. This decree recognized Christianity as a legitimate religion, on a par with the official Pagan state religion, Judaism, many mystery religions, etc. A period of religious struggle began, mainly between the established Pagan polytheistic state religion and Christian monotheism.

Author Jonathan Kirsh has written about conflicts between paganism and monotheism in the 4th century Roman Empire and at other times and locations. He asserts that exclusivist monotheism which believes "... that only a single deity is worthy of worship for the simple reason that only a single deity exists" -- holds primary responsibity for thousands of years of religious intolerance and persecution, up to and including the 9/11 terrorist attacks. He describes the latter as "only the most recent example of the violence that men and women are inspired to commit against their fellow human beings by their true belief in the Only True God." He suggests that polytheism is generally more tolerant. "At the heart of polytheism is an open-minded and easygoing approach to religious belief and practice ... [in comparison with monotheism's dangerous] tendency to regard one's own rituals and practices as the only proper way to worship the one true god." ₅

In 380 CE, Emperor Theodosius declared Christianity to be the official religion of the Roman Empire. The general mood of religious tolerance that had been prevalent in the Empire ended. Widespread tolerance was not to return to Europe until the Enlightenment.

Persecution of Pagans during the reign of Constantius II:

Constantine's son, Constantius II, was a Christian and a fierce opponent of Paganism. In 353 and 356 CE, he issued decrees that closed all of the Pagan temples, made the practice of sacrifices to the ancient Gods and Goddesses a capital crime, and even executed anyone who attended sacrifices or worshiped idols. One of his favorite sayings was: "Cesset superstitio; sacrificiorum aboleatur insania" (Let superstition cease; let the folly of sacrifices be abolished). Initially, the edicts had little effect because of the loyalty of the Pagan Roman public to their traditional religions. Even followers of mystery religions had retained a nominal allegiance to the Roman deities. "There is no evidence that this law was widely enforced." _1,2

Yet, in 357 CE he confirmed privileges to the Vestal Virgins and enacted a law confirming the prerogatives of the Pagan priests. However, in response to complaints by some Christian Senators he removed the Altar of Victory in the Senate house. This is an altar where Senators had traditionally made a sacrifice before entering the chambers. Constantius apparently did not attempt to stop the Christians from destroying and pillaging many of the ancient temples.

A convert to Christianity, Firmicus Maternus, commented:

"Paganism, most holy emperors, must be utterly destroyed and blotted out, and disciplined by the severest enactments of your edicts, lest the deadly delusion of the presumption continue to stain the Roman world. ... How fortunate you are that God, whose agents you are, has reserved for you the destruction of idolatry and the ruin of profane temples."

Even though the edicts and persecution were not widely applied to the Pagan public, many converted to Christianity. Wikipedia comments:

"The edicts which legislated against pagans, beginning with Constantius, would in time have an unfavourable influence on the Middle Ages and become the basis of the much-abused Inquisition. ₁

Persecution of Christians partly reintroduced under Emperor Julian (361-363):

Emperor Julian appeared to be at least a nominal Christian in public. However, he was initiated into at least three Pagan mystery religions. He rejected Christianity because of its exclusivism -- its claim to be the only true religion. Once emperor, he tried to reverse the oppression of Paganism and to reorganize the old religion's doctrines, rituals and liturgy. His hope was to unite all Pagan religions under one belief system.

He forbade the teaching of ancient classical works to Christians; this prevented them of entering a profession. He removed special privileges given to the Christian clergy by Constantine. He ordered Christians who had demolished pagan temples to rebuild them or pay for their reconstruction. Otherwise, Christians were not persecuted during his short reign.

Because of his promotion of tolerance for the old religion of Rome, Julian was called "Julian the Apostate."

Tolerance of Pagans and Christians under Jovian , Valentinian (364-375) and Valens (364-378):

Jovian created a climate of religious tolerance during his brief reign of 363-364 CE. This policy continued by his successors Vanentinian, who ruled the Western part of the Roman Empire and Velens who ruled the East. Valentinian confirmed the rights and privileges of the Pagan priests and allowed them to have control over their temples. Still, "... unofficial destruction of pagan holy sites, notably by such Christians as Martin of Tours," was tolerated. ₁

Renewal of persecution of Pagans under Gratian, Theodosius I, & Valentinian II:

Emperor Gratian succeeded Valentinian in the West; Ambrose, the Bishop of Milan, became his chief advisor. Theodosius succeeded Valens in the East.

Historian Samuel Dill wrote:

"In the long truce between the hostile camps, the pagan, the skeptic, even the formal, the lukewarm Christian, may have come to dream of a mutual toleration which would leave the ancient forms undisturbed. But such men, living in a world of literary and antiquarian illusions, know little of the inner forces of the new Christian movement." ₄

In 382 CE, Gratian:

	Appropriated the income of Pagan priests and Vestal Virgins;
	Confiscated the personal possessions of the priestly colleges while terminating their privileges and immunities;
	Confiscated all of the Pagan temples and shrines along with their revenues; and
	Resigned as Pontifex Maximus -- the head of the old religion -- and abolished the office. 1

During the same interval, Theodosius extended religious tolerance in the East: he did not oppress Pagans; in 388, he ordered that a Jewish synagogue be rebuilt at Callicinum in Mesopotamia after it had destroyed by a bishop and his fellow Christians.

Pagans enjoyed renewed religious freedom after the death of Gratian. Many Pagans achieved important offices. A law of 386 stated that Pagans were given exclusive responsibility to maintain their temples and celebrate their festivals. However, Valentinian II later reinstated Gratian's oppressive regulations against Pagans in the west. In 391 he issued a decree that again prohibited sacrifices and even forbade anyone from visiting the temples. He was murdered and replaced by Eugenius, a professor of rhetoric.

Decline of Paganism in the very late 4th century:

According to Wikipedia: ₁

"In the year 391 in Alexandria in the wake of the great anti-pagan riots 'busts of Serapis which stood in the walls, vestibules, doorways and windows of every house were all torn out and annihilated..., and in their place the sign of the Lord's cross was painted in the doorways, vestibules, windows and walls, and on pillars'."

Serapis (a.k.a. Sarapis, Zaparrus) was a composite of several Egyptian and Greek Pagan deities. He was introduced in Egypt during the reign of Ptolemy I, and lasted well into the Roman period. He formed a link between Greek and Egyptian Pagan religions. ₈

"Rome was more pagan than Christian up until the 390's; Gaul, Spain and northern Italy, in all but the urban areas, were pagan, save Milan which remained half pagan. In the year 392, Theodosius officially began to proscribe the practice of Paganism. This is apparently the time in which he authorized the destruction of many temples throughout the empire. Theodosius issued a comprehensive law that prohibited the performance of any type of Pagan sacrifice or worship, even within the privacy of a person's own home. Theodosius prohibited men from privately honoring their Lares with fire, their Genius with wine, or their Penates with incense. Men were prohibited from such traditions as burning candles or incense and suspending wreaths in honor of the deities. Theodosius also prohibited the practice of all forms of divination, even those forms of divination that were not considered harmful to the welfare of the Emperor, with this wide-ranging law. Paganism was now proscribed, a 'religio illicita'."

"In 393, Theodosius was ready to begin his war against Eugenius and Arbogastes. The battle that ensued became, in essence, a battle for the survival of Paganism. The defeat of Eugenius by Theodosius in 394 led to the final separation of Paganism from the state. Theodosius visited Rome to attempt to convert the Pagan members of the Senate. Being unsuccessful in this, he withdrew all state funds that had been set aside for the public performance of Pagan rites. From this point forward, state funds would never again be made available for the public performance of Pagan rites nor for the maintenance of the Pagan temples. Despite this setback on their religion, the Pagans remained outspoken in their demands for toleration. Many Pagans simply pretended to convert as an obvious instrument of advancement."

"[Philip Hughes wrote:] 'Theodosius was not the man to sympathise with the balancing policy of the Edict of Milan. He set himself steadfastly to the work of establishing Catholicism as the privileged religion of the state, of repressing dissident Christians (heretics) and of enacting explicit legal measures to abolish Paganism in all its phases'."

"Examples of the destruction of pagan temples in the late fourth century, as recorded in surviving texts, describes Martin of Tours' attacks on holy sites in Gaul, the destruction of temples in Syria by Marcellus, the destruction of temples and images in, and surrounding, Carthage, the Patriarch Theophilus who seized and destroyed pagan temples in Alexandria, the levelling of all the temples in Gaza and the wider destruction of holy sites that spread rapidly throughout Egypt. This is supplemented in abundance by archaeological evidence in the northern provinces (for which written sources hardly survive) exposing broken and burnt out buildings and hastily buried objects of piety. The leader of the Egyptian monks who participated in the sack of temples replied to the victims who demanded back their sacred icons: 'I peacefully removed your gods...there is no such thing as robbery for those who truly possess Christ'.^"

"According to a Christian historian 'Paganism was now dead', though pagans survived and would continue to do so for another three centuries, mainly outwith the towns -- 'rustics chiefly - pagani'." ₆

"Edward Gibbon wrote:

'The generation that arose in the world after the promulgation of the Imperial laws was attracted within the pale of the Catholic Church: and so rapid, yet so gentle, was the fall of paganism that only twenty-eight years after the death of Theodosius the faint and minute vestiges were no longer visible to the eye of the legislator'." ₇