Throughout western civilization, the Catholic Church has been one of the most powerful and influential institutions since the dawn of humanity. It has commanded armies in holy wars, made or broke kings and emperors, all while being a shared facet of life for all of humanity for 2,000 years. The church quickly rose to prominence in the late antiquity of the Roman Empire. The relationship between the Christian church and the Imperial throne dramatically changed in between the 3rd the 5th century. The Christians went from being under extreme persecution by pagans to persecuting pagans in the same manner. Roman emperors tried to purge Christianity from the empire under the rule of Diocletian and Galerius. Constantine would conquer the empire wielding the power of the Christian God. Theodosius would submit himself to the power of that same God forever changing the relationship between church and state. The authority of Christianity withstood even the fall of the Roman Empire.

In the history of the early church Christians endured a prolonged persecution. The intensity of harassment varied and when political opposition towards Christians was high, so grew the list of Christian martyrs. But before the persecution during the reign of Diocletian and Galerius, Christians had a relatively peaceful existence in the empire. In the 290s the new generation of Christians did not personally experience the oppression of past persecutions, and so, were softer in the face of political opposition. Justo L. Gonzalez is a historian of Christianity and in his book The Story of Christianity: Volume 1 he points out that Diocletian’s wife and daughter were Christians themselves. Thus, Christians had few concerns towards the new Augustus’ policy. Historians believe it was the Caesar under Diocletian, Galerius, who advocated for a persecution of Christians. Galerius had come to believe Christians were dangerous when, over the issue of military service, Christians were put to death, either for attempting to leave the army or refusing to join. With pressure from Galerius, Diocletian banned all Christians from the military and high-level positions in the imperial bureaucracy. Gonzalez notes, “Even then, the purpose was not to kill Christians, but to remove them from positions of responsibility within the empire.” This was harsh, but, it was comparable to persecutions of the past. The Romans were great at knowing how much pressure they could place on a group of people without causing chaos.

However, sentiment towards the Christians grew even worse when two fires broke out at the Imperial Palace. Who started the fires remains a mystery, and some historians suggest that it was Galerius himself, regardless it was the Christians who were blamed, adding to the paranoia of Diocletian. Church leaders were soon arrested, and captured Christians were required to make sacrifices to the pagan gods, or be subject to imprisonment, torture, and death. Eusebius of Caesarea, a Christian historian who lived during this tumultuous time, writes.
“royal edicts were published everywhere, commanding that the churches be leveled to the ground, and the Scriptures be destroyed by fire, and ordering that those who held places of honor be degraded, and that the household servants, if they persisted in the profession of Christianity, be deprived of freedom. Such was the first edict against us. But not long after, other decrees were issued, commanding that all the rulers of the churches in every place be first thrown into prison, and afterwards by every artifice be compelled to sacrifices.”

Eusebius of Caesarea, 260-339 C.E., was the first known historian of the Christian Church, he lived through the persecution, the civil wars, and to see the Roman Empire under the rule of Constantine the Great. Douglas Foster mentions that “Eusebius’s approach to historiography is unique in several ways. He was the first Christian apologist to bring the literary-historical point of view to his works.” His method of writing church history would be emulated throughout the middle ages. Eusebius saw the dominance of the Christian church as a success and had a very favorable view of Constantine because of it. When referencing Eusebius, we should keep his biases in mind. His work in Church History is an invaluable primary source.

The emperors Diocletian and Galerius saw Christians as an immoral and deviant group, and when Diocletian retired from the throne, Galerius rose to the rank of Augustus. The persecution continued under his reign. And as Gonzalez says, “the lists of martyrs grew longer and longer, there seemed to be no end in sight.” However, the persecution was not carried out in all parts of the empire. In the territories to the west two emperors, Maxentius and Constantine, refused to legitimize the policies of their rival Galerius. Civil war would soon consume the Roman empire, and one Emperor would be left standing. The life of Constantine the Great would dramatically change Christianity, and the world. The effects would last for over a millennium.

The civil wars, during which Constantine rose to become the sole ruler of the Roman Empire, is an endlessly fascinating period of history. A few instances during this time are significant to the rise of Christianity’s power. First, this is the story of the Death of Emperor Galerius, the orchestrator of the great persecution. Galerius believed that Christianity was a danger to the Empire. He was afraid of the God of the Christians, and this shows in his last days. Eusebius of Caesarea wrote that Galerius became painfully ill and, believing that this was a punishment from the Christian God, switched his policy on the Christians. According to Eusebius, Galerius thought he was restoring the tradition of the old Romans, and wanted to protect the worship of pagan ancestor. He claims that the Christians had been resilient in the face of punishment and said “therefore, moved by our mercy to be benevolent toward all, it has seemed just to us to extend to the m our pardon, and allow them to be Christians once again, and once again gather in their assemblies, as long as they do not interfere with public order.”

Five days after issuing this edict, Galerius would die. Eusebius is biased in his writing, and there is a chance that there were other reasons Galerius decided to end the persecution on his death bed. It is hard to believe that an Emperor who fought against Christianity for so long would have suddenly realized the cruelty he brought. It is hard to place yourself in the position of someone nearing the end of their life. Did Galerius believe the Christian God would lift his illness from him if he ended the persecution? Regardless of Galerius’ true intentions Christians would come to understand what he wrote. Galerius feared the Christian God, just as he had feared the Christians. And so, Christians interpreted the end of the persecution as divine intervention from God. This was proof that their God had power over even a Roman Emperor, who was to pagans partly a god himself. Constantine would use this power of Christ to his advantage in war.

After the death of Galerius, the empire was divided among four emperors: Licinius and Maximinus Daia in the East, Maxentius, and Constantine in the West. But, soon the other three saw Maxentius as illegitimate, and this gave Constantine an opportunity he was waiting for. Much to Maxentius’s surprise, Constantine marched his army over the Alps and towards Rome resembling nothing so much as when Julius Caesar himself marched on the Eternal City. Maxentius gathered his army outside of Rome, ready for battle. According to Christian historians, prior to the battle, Constantine had a vision or a dream from God. Eusebius claimed that Constantine saw in the sky “In this you shall conquer.” Gonzalez writes, “Constantine ordered that his soldiers should use on their shield and on their standard or labarum a symbol that looked like the superimposition of the Greek letters chi and rho…these are the first two letters of the name Christ.” The Battle of the Milvian Bridge was a victory for Constantine and gave him control over the Western Roman Empire.

Christians saw the story of his vision from God as further proof of the power of their God. Now the Christian God had the power to win or lose battles for an emperor, and Constantine’s relationship with God would only become more apparent.
After his defeat over Maxentius, Constantine struck an alliance with Licinius and came to an agreement that the persecution of Christians would end. The resulting agreement produced the Edict of Milan, which gave unprecedented legal protection for Christians in the Empire. The edict under the authority of both Constantine and Licinius granted “to the Christians and other full authority to observe that religion which each preferred.” While most of the text focuses on Christians, the Edict of Milan was not placing Christianity over any other faiths at the time. “This regulation is made that we may not seem to detract from any dignity or any religion” The edict went far to heal the wounds caused by the persecution under Diocletian and Galerius by given by confiscated Christian property. It said,
“Christians are known to have possessed not only those places in which they were accustomed to assemble, but also other property, namely the churches, belonging to them as a corporation and not as individuals, all these things which we have included under the above law, you will order to be restored, without any hesitation or controversy at all, to these Christians.”

No simple gesture, the Edict of Milan was intended to be spread everywhere and be announced to all. This was a huge boon to Christians all over the empire, and it is no wonder that church officials like Eusebius and others who still bore the marks of torture looked to Constantine as a hero and champion of faith. It is ironic though, that Constantine was not a Christian himself. He would only be baptized on his death bed. Until then Constantine had a long bloody road as he fought to become the sole ruler of the Roman World. He would defeat Maximinus Daia, the successor of Galerius who did not recognize the Edict of Milan and still persecuted Christians. And eventually, he would turn on his ally Licinius, whose character became tainted to the eyes of Eusebius or Caesarea. Despite being involved in the Edict of Milan, Eusebius would portray Licinius as a tyrant whose Wickedness led to his death.

And so, with Constantine’s rise to absolute authority came the marriage of the Christian church with Imperial influence. The church, now with the support of the emperor, would not be the same. The Bishops and other members of church hierarchy gained new marks of status and prestige. Church property was exempt from taxes, as were the bishops who also were free of military conscription and now had open access to all imperial posts. Bishops wearing luxurious garments now had judiciary powers which led to corruption by the use of bribes. It seemed possible now for someone to buy their way into high offices of the church. But bishops weren’t the only beneficiaries. The first day of the week was put aside for a day of worship, thus beginning the weekly cycle we still recognize today. Christians now had the pleasure of going to beautiful churches freshly built by orders of the emperor. Even the image of Christ was altered by this Imperial influence. Christians now knelt as they prayed the same as if addressing an emperor. Jesus, the carpenter, was now depicted as sitting on a throne as ruler of the universe. All of this saw to a massive surge in popularity for the church. The number of converts was so much that much of the usual initiation process of becoming a member of the church was skipped. Now many new members of the church carried in with them beliefs and ideas the early church would have disliked. The power of the church was emerging with the power of the emperor, but Constantine still held personal sway over church doctrine.

Gonzalez states that “Constantine hoped that the church would become the cement of the empire.” But that foundation he sought after was soon on shaky ground as the church stood divided on the Aryan controversy. The argument arose during Constantine’s wars with Licinius and threatened the unity of the church. Constantine called an Ecumenical Council in 325, the Council of Nicea. Here about 300 church officials still recovering from the persecution saw for the first time a physical manifestation of Christian organization. Gonzalez sets the scene: “Many of those present knew of each other via hearsay or through correspondence. But now, for the first time in the history of Christianity, they had before their eyes physical evidence of the universality of the church.” The satisfaction that those like Eusebius of Caesarea must have felt is hard to imagine. Finally, it seemed that all their faith and hard work was making a difference. However, the true power lay not in this body of men but with the emperor. “Now it was possible to invoke the authority of the state to settle a theological question.” The state, not the church would decide what was officially Christian. The Aryans were cast aside, for now, and Constantine banished the dissenting priests from their native cities. The issue of Arianism would not go away though, because after Constantine died those who inherited the throne shared different faiths. Some favored the Nicene ideas but others Aryanism. Both sides would enjoy imperial support until the Edict of Thessalonica made Christianity the only religion of the empire and outlawed both Aryanism and Paganism.

In 380 the Emperor Theodosius was stricken ill and so, preparing for death, was baptized by a Nicean Bishop. This may have played a significant role because after he recovered, Theodosius became loyal to Nicean Christianity. That same year, emperors Gratian, Valentinian and Theodosius issued the Edict of Thessalonica, bringing unity to the church and woe to heretics and pagans. It stated, “We authorize the followers of this law to assume the title of Catholic Christians; but as for the others, since, in our judgment, they are foolish madmen, we decree that they shall be branded with the ignominious name of heretics.” These heretics would suffer “chastisement” and “divine condemnation” In 382, Emperor Gratian ended financial support for paganism, in 391 Theodosius banned pagan sacrifices and ordered temples closed, and in 392 all pagan worship was forbidden. Once it was pagans who had persecuted the Christians but now the roles were reversed. The use of violence against pagans, and Jews, was rarely punished and zealous priests were fond of ordering the destruction of pagan shrines and buildings. It only took 100 years for the Roman world to be turned upside down, or had it? Emperors still warred among one another, minorities were still persecuted for their beliefs, and most people were subjects to the wealthy and powerful.

Theodosius may have felt obligated after receiving baptism from the Nicean bishop, and he may have even credited his recovery as an act of God. At this point the relationship between Christianity and the Emperor changed from the time of Constantine. Constantine believed in the power of the Christian God but still sought to use it for his means. He controlled the direction of the church, and the church looked to Constantine for that direction. It is telling that Constantine is remembered both as a saint and a pagan god. He would not let religion define him; rather it was the opposite. Theodosius was not the same. He felt bound to God and was concerned for his soul and everlasting life. His actions on earth sought to please the church. In 390 a small revolt in the city of Thessalonica brought the ire of Theodosius. Jamie Joosten writing for St. Ambrose University says, “As soon as Theodosius heard of the uprising, he ordered an immediate retaliation. The army units sent to Thessalonica acted as if they had captured a hostile city. Over 7,000 citizens were murdered.” Theodosius was already regretting the slaughter when he received a letter from Ambrose the Bishop of Milan, condemning Theodosius for the massacre. Ambrose was arguably the most prominent member of the church at the time, and his opinion carried great weight. Ambrose threatened that he would not offer sacrifice in the emperor’s presence unless he would repent, and Ambrose personally scolded Theodosius when the emperor tried to attend mass. Fearing for his soul, Theodosius apparently spent eight months begging the bishop for forgiveness, even to the point of moaning and crying before Ambrose. And so it came to pass, that the Emperor of the Roman Empire, the most powerful man in western society, submitted himself to a bishop of the Catholic Church.

The Catholic church would outlast the Western Roman Empire and continue to wield power and influence over the kingdoms that followed. But it is important to remember how Christianity came to use that power. It can be said that when the church was infected with wealth and power at the time of Constantine’s reign, it had started to become corrupt. Different sects of Christianity fought with themselves over official church doctrine and once given the power; the church persecuted pagans to the extent that they were persecuted themselves. In history, the changes that occur over time can overshadow what stays the same. Humans are selfish and tribalistic. We have ingroups, and we have outgroups. The majority always uses its power and influence to disenfranchise the minority. Once the church was given power we see that they became the same as those who had persecuted them, but there is another side to this view. Millions of people throughout the history of Christianity have shared this one faith. I believe that while the Western Empire fell the reason that the church did not fall with it was that Christians continued to believe. Christianity does not rely on power, doctrines, or wealth and orderly institutions. It relies on faith alone and all the unnamed people in history that continued the tradition of that faith.


Constantine Augustus, Licinius Augustus. The Edict of Milan. 313 C.E.

Eusebius of Caesarea. Church History. 340 C.E.

Foster, Douglas A. “Eusebius of Caesarea.” Salem Press Biographical Encyclopedia (January 2015): Research Starters, EBSCOhost (accessed May 30, 2017).

Gonzalez, Justo L. The Story of Christianity. New York: HarperCollins, 2010.

Gratian, Valentinian, Theodosius. Edict of Thessalonica. 380 C.E.

Joosten, Jaimie. Theodosius and the Relationship Between Church and State. St. Ambrose University.