While the Christianization of the Roman Empire is commonly attributed to Emperor Constantine and his celebrated Edict of Milan in 313, Rome’s conversion was no less due to the efforts of another, the great Theodosius, who reigned at the close of the fourth century, from 379 to 395. It was Theodosius who completed the grand work of Christianization that Constantine had begun and ensured that the Roman Empire committed itself to Catholic Christianity specifically, as opposed to one of the many heretical variants then in vogue. But before we credit his work, let us review the status of Christianity in the years leading up to the reign of Theodosius, so we can properly understand his importance.
In 313, Constantine issued his Edict of Milan following his victory over a rival imperial claimant at the Battle of the Milvian Bridge. The Edict of Milan brought a formal end to the decade of anti-Christian legislation that had begun with Diocletian’s edict of persecution in 303. Constantine’s edict granted Christians legal recognition, including the rights to worship, own property, and proclaim the faith openly, and have recourse to Rome’s courts to enforce legal claims. Further acts of favor would follow, such granting the Church and its clergy tax immunity in 315 and generous donations of land to the popes. Constantine’s edict thus represented a turning point for Christianity in the empire, not only placing it on par with paganism but endowing it with a special status through imperial patronage.
It was not these actions which turned the empire Christian, however. Historians speculate that Christians in the time of Constantine comprised as little as one tenth of the imperial populace, and Christianity continued to exist side-by-side with paganism for decades. In fact, to someone living in the generation after Constantine, his support for Catholic Christianity may have seemed a momentary aberration. Constantine’s successor, Constantius II (r. 337-361), embraced Arianism and persecuted Catholic clergy who openly opposed him—such as St. Athanasius, who was banished by Constantius and even once had a death sentence passed against him in absentia.
Following Constantius’s death, his cousin Julian took the throne in 361 and undertook the monumental task of reversing course and bringing Rome back to paganism. From 364 to 378, Rome was again under the dominance of the Arians in the person of Emperor Valens. By the time Valens died in 378, Catholic Christianity had been out of favor for over 40 years and was considered passé by some. Any objective observer in 378 would have assumed Rome’s future lie with some sort of Arian-pagan synthesis.
That changed with the ascent of the Spanish general Theodosius to the throne in 379. The son of a prominent Spanish count, Theodosius inherited an empire divided politically and religiously. With his power center primarily in the East, Theodosius had to contend with a rival emperor, Gratian, in the West, who grudgingly accepted Theodosius’s ascension as co-emperor. Religiously, the empire was divided three ways between Arians, Catholics, and pagans, the latter of which probably comprised two thirds of the population. Catholics and Arians strove for imperial patronage while pagans resented the growing influence of Christianity in society.
While Arianism was strongest in the East, Theodosius, a Spaniard, came from a region known for its impeccable orthodoxy and was a staunch Catholic. Once in power, he resolved to use the full weight of the imperial government to settle the long-standing rivalry between Catholics and Arians. In 380, he issued a proclamation known as the Edict of Thessalonica, which declared that only those who “profess that religion which was delivered to the Romans by the divine Apostle Peter as it has been preserved by faithful tradition and which is now professed by the Pontiff Damasus [Bishop of Rome]” were allowed to call themselves Catholic Christians. As for heretics, Theodosius had some choice words:
As for the others, since in our judgement they are foolish madmen, we decree that they shall be branded with the ignominious name of heretics and shall not presume to give to their conventicles the name of churches. They will suffer in the first place the chastisement of the divine condemnation and in the second the punishment of our authority that in accordance with the will of Heaven we shall decide to inflict.
Though historians debate how effective this law was in rooting out heresy (as heretical sects would continue to flourish in the East for centuries), it is certain that Theodosius’s edict established Catholicism as the officially sanctioned religion of the court, giving it a powerful edge over competing heretical sects and marking the decline of Arianism—at least in its influence over the Eastern Empire.
Theodosius followed up his decree with vigorous actions against the Arians, expelling the Arian Patriarch of Constantinople in 380 and summoning a council the following year to definitively settle the matter of Arianism and maintain doctrinal unity between East and West. The resulting gathering was the Second Ecumenical Council of Constantinople, which reaffirmed the decrees of Nicaea and condemned Arianism along with other heresies.
Theodosius’s attitude towards paganism was a bit more cautious. He knew that pagans constituted the numerical majority of his subjects and that he had to tread lightly. On the other hand, with the power of the state firmly in his hand, he had considerable leeway to nudge Roman society away from paganism and towards Christianity. He allowed pagans to practice their religion openly, so long as certain customs deemed especially offensive or impious to Christians were avoided, especially animal sacrifice and divination. Pagan holy days were converted into workdays, but the festivals associated with them were allowed to continue. Many pagan temples were closed or destroyed during Theodosius’s reign as well, though historians debate the degree to which Theodosius himself ordered this. He also intervened occasionally to discourage the restoration of paganism, as in 391 when he personally acted to stop the Roman Senate (largely pagan) from restoring the so-called Altar of Victory, a centuries’ old altar with a golden statue of the goddess victory.
Until 392, Theodosius ruled with a co-emperor in the West, first Gratian then Valentinian II. When the latter died in 392, Theodosius ruled the entire empire directly, the last Roman Emperor to hold undivided sway over both East and West. In his last years, a flurry of anti-pagan legislation emanated from Constantinople, part of a legal text known as the Theodosian Code. The religious sections of the Theodosian Code seem written to extirpate heresy and strictly punish continued adherence to paganism. While some of the punishments mandated by the code sound draconian, there is little evidence that these penalties were ever carried out. The anti-pagan proscriptions of the law seemed to have been enforced most stridently in the environs of Constantinople proper. Elsewhere in the empire, paganism continue to exist alongside Christianity in a spirit of competition, dying slowly between the 5th and 6th centuries.
Theodosius’s reign marked a kind of watershed in late Roman history. Theodosius himself was not always the paragon of Christian virtue; indeed, one of his claims to notoriety was his massacre of the people of Thessalonica, which got him excluded from the sacraments by St. Ambrose. Nevertheless, he did play an instrumental role in completing the Christianization of the empire begun under Constantine. While paganism and heresy were not entirely extirpated in his day, Theodosius’s legislation ensured the ascendancy of Catholicism and rendered its triumph inevitable.
Image from Wikimedia Commons
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