The Great Persecution

By Thomas V. Mirus ( bio - articles - email ) | May 11, 2026 | In Lives of the Popes

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The first decade of the fourth century, from about 302 to 313, is one of the most remarkable in history. In that short time, the Church would go from the worst of persecutions to the beginning of an unprecedented new era of peace and favor. In what we might consider a foreshadowing of the Church’s trials and final victory at the end of the world, the Great Persecution was merely the labor pains for the birth of Christendom.

29—St. Marcellinus (296-304)

This pope is not the St. Marcellinus named in the Roman Canon, though they died in the same year. We know nothing certain of his reign, other than that he ordered structural modifications to the cemetery of St. Callistus.

The most important thing about this pope is simply that he saw the beginning of the last and worst persecution the Roman Church ever faced. The Emperor Diocletian ruled from 284 to 305, and for all but the last three years of his reign, Christians enjoyed peace, favor, and prosperity. But over the course of his reign, Diocletian increasingly decided to share his rule, ultimately establishing a tetrarchy with himself as Augustus in the East, Maximian as Augustus (co-emperor) in the West, and under them the junior Caesars Galerius in the East and Constantius Chlorus in the West.

The Catholic Encyclopedia explains how the Great Persecution came about:

Had Diocletian remained sole emperor, he would probably have allowed this toleration to continue undisturbed. It was his subordinate Galerius who first induced him to turn persecutor. These two rulers of the East, at a council held at Nicomedia in 302, resolved to suppress Christianity throughout the empire. The cathedral of Nicomedia was demolished (24 Feb., 303). An edict was issued “to tear down the churches to the foundations and to destroy the Sacred Scriptures by fire; and commanding also that those who were in honourable stations should be degraded if they persevered in their adherence to Christianity” (Eusebius).

Three further edicts (303-304) marked successive stages in the severity of the persecution: the first ordering that the bishops, presbyters, and deacons should be imprisoned; the second that they should be tortured and compelled by every means to sacrifice; the third including the laity as well as the clergy. The atrocious cruelty with which these edicts were enforced, and the vast numbers of those who suffered for the Faith are attested by Eusebius and the Acts of the Martyrs. We read even of the massacre of the whole population of a town because they declared themselves Christians.

The abdication of Diocletian (1 May, 305) and the subsequent partition of the empire brought relief to many provinces. In the East, however, where Galerius and Maximian held sway, the persecution continued to rage. Thus it will be seen that the so-called Diocletian persecution should be attributed to the influence of Galerius; it continued for seven years after Diocletian’s abdication.

As for Pope St. Marcellinus, the Donatist heretics a century later spread the story that he had apostatized by obeying the order of Diocletian to surrender the sacred books and offer incense to pagan gods. There is no contemporary evidence of this, but what adds credibility to the story is that Marcellinus was deliberately omitted from lists of the popes published in the 4^th, 5^th, and 6^th centuries (the first of which was published only three decades after his death), indicating that the authors of these lists did not approve of him.

Pope Marcellinus offers incense to an idol with St. Peter behind him.

Against the story of Marcellinus’s apostasy, some say that St. Augustine rejected the accusation of the Donatists—but a close reading of his response shows that he does not confidently assert that they were wrong on the facts, even if he rejects their argument that this event would discredit the Roman Catholic Church.

Only in the late 5^th and early 6^th centuries, when the apostasy of Marcellinus was generally accepted as fact, did a legend arise that he had quickly repented of his apostasy before a council of bishops, after which he confronted Diocletian and became a martyr. But St. Augustine himself, had he known of St. Marcellinus’s martyrdom, surely would have mentioned it in his defense.

On the other hand, there are indications that Christians in Rome venerated St. Marcellinus’s tomb early on. And he was venerated as a saint in the Catholic Church for over a millennium, until 1969, when Pope St. Paul VI removed him from the liturgical calendar precisely because of these uncertainties, to which we can find no definite resolution.

30—St. Marcellus I (308-9)

Though the last great persecution of Christians in the Western Roman Empire wound down with the abdication of Diocletian in 305, it still took almost two years after the death of St. Marcellinus in 304 for a new pope to be elected—and that new pope, St. Marcellus I, did not actually take office until the beginning of 308. Marcellus found the Roman Church in a very chaotic state after such a terrible trial, and while very little is known about this pope, we at least know that he did much to reorganize the local Church.

As usual in time of persecution, a large number of Christians had fallen away. However, while earlier popes had faced opposition for their leniency, Marcellus was attacked for his strictness. The new generation of lapsi were not satisfied with the merciful policy established by earlier popes, by which former apostates might return after doing appropriate penance. Instead, they wanted to be readmitted to communion without having to do any penance at all!

In his epitaph for St. Marcellus, Pope St. Damasus Iater described the situation:

The truth-telling ruler, because he bade the lapsed weep for their crimes, became a bitter enemy to all these unhappy men. Hence followed rage and hate, and discord and strife, sedition and slaughter. The bonds of peace are loosed. On account of the crimes of another, who denied Christ in time of peace, he was driven from the borders of his fatherland by the savagery of the tyrant. Damasus wishes briefly to tell these things which he had found out, that the people might know the merit of Marcellus.

As Damasus indicates, these seditious lapsi were led by a man who had apostatized even before the persecution began. The conflict within the Roman Church reached the point of physical violence, and as a result of this disturbance of the peace, the Western Emperor Maxentius exiled St. Marcellus, who died shortly thereafter. He was buried in the Catacombs of St. Priscilla.

An alternate legendary account of St. Marcellus’s punishment by the emperor states that he was condemned to work as a slave attending to horses at a station on the public highway, and died in that position.

31—St. Eusebius (310)

St. Eusebius is said to have been Greek, and to have reigned for perhaps as little as four months.

He faced the same conflict as St. Marcellus, as St. Damasus’s epitaph for him in the cemetery of St. Callistus relates:

Heraclius [leader of the apostate party, remembered as an antipope] forbade the lapsed to lament their sins,
Eusebius instructed the wretched to weep for their faults.
The people are broken into parties, with fury blazing up.
Sedition, murder, war, discord, quarrels.
Suddenly they were equally struck by the savage rage of the tyrant [Maxentius],
although the bishop preserved untouched the pacts of peace.
Joyous he preferred exile with the Lord as his judge;
he abandoned the world and his life on the Trinacrian [Sicilian] shore.

For Eusebius, bishop and martyr
An admirer and friend of Father Damasus,
Furius Dionysius Filocalus prepared this.

32—St. Miltiades (311-14)

The reign of St. Miltiades saw the beginnings of a complete and permanent change in the status of Christianity in the Roman Empire.

Just before Miltiades’s election, the Emperor Galerius issued an edict of toleration ending the persecution in the Eastern half of the Empire. As mentioned earlier, Galerius is said to have egged Diocletian on to begin the Great Persecution in the first place, but during his final illness he softened, and apparently even requested that Christians pray for him.

Then after Miltiades’s election, the Western Emperor Maxentius (for the Roman world was now ruled by two emperors) restored Church property that had been confiscated during the Great Persecution.

The coup de grace came with the victory of Constantine over Maxentius at the Milvian Bridge in 312, followed by the Edict of Milan on February 13, 313, by which Constantine and Licinius, his co-emperor in the East, legalized Christianity (along with all other religions) throughout most of the Roman Empire.

The new dispensation allowed St. Miltiades to get down to some serious administrative work in the diocese of Rome. Providentially, it was at this time that the Church received as a gift from Constantine what would become the papal residence and administrative headquarters, the Lateran Palace (formerly the palace of Constantine’s wife, Fausta)—which of course was or would later be connected to the Lateran basilica, which became the cathedral of the Bishop of Rome.

It was at the Lateran Palace that Pope Miltiades held the Synod of Rome in 313. This was a response to a schism in the Church at Carthage over the election of Bishop Caecilian. We see here the emergence of a major new heretical sect, Donatism. Like previous rigorist parties, Donatus and his followers denied the validity of the baptisms and ordinations of schismatics and heretics, and so they insisted that priests and bishops who came into the Church from such groups must be re-baptized and re-ordained.

The Donatists appealed to Constantine, who asked the pope to hear their case, co-adjudicated by three bishops from Gaul (a region whose Holy Orders the Donatists would accept since there had been no persecution there). St. Miltiades agreed, but expanded this assembly into a proper synod, rather than a mere state-ordered commission, by adding fifteen more bishops from Italy. In three sessions over three days, the Synod examined the matter with a rigorous Roman-style civil procedure. This was too much for the Donatists; unable to provide any documentary proof of their claims, they left without even making their case.

So Miltiades and the eighteen bishops at the synod condemned Donatus for rebaptizing bishops and priests, and ruled in favor of Caecilian as bishop of Carthage. Miltiades’s verdict ended with these words:

Since it is patent that Caecilian has not been accused in respect of his calling by those who came with Donatus, and it is patent that he has not been convicted in any regard by Donatus, I judge that he should continue to be held in good standing by his ecclesiastical communion.

The emperor had instructed Miltiades, “I do not wish you to leave schism or division of any kind anywhere.” But the Synod’s judgment against Donatus did not succeed in ending the schism, and so when the Donatists appealed again to Constantine, he convened the Council of Arles in 314 to re-adjudicate the matter. Perhaps, as later at the Council of Nicaea, Constantine was more concerned with the peace of the state than with correct doctrine. But this council only condemned the Donatists again. St. Miltiades died before the council was held, but the legates of his successor St. Sylvester, newly installed bishop of Rome, were present on the pope’s behalf.