Nero
The infighting between members of what was to become the Church of Rome and other Christians in both Rome and Alexandria could hardly be called persecution but it certainly attracted the attention of the emperors.
According to Roman church records there were mass executions by Nero. I was taught at school that he lit his garden with human torches. Tacitus writing at least fifty years later agreed that the punishment of christians was “extreme.” However Suetonius writing earlier than Tacitus including the punishment of christians in one sentence with measures taken to discipline charioteers and the banning of Pantomimes from the central city area. In any case there are problems of veracity with both these histories as we only know of their content through copies made in the eleventh century and the copies were made by monks affiliated to the Church of Rome.
Vienne
In the year 177 there was a very specific persecution of christians in Vienne which was in the Rhone valley. The events surrounding this persecution are captured in a very moving narrative from the Christian brethren comprising churches established at Lyons and Vienne. Commonly referred to as “The Epistle of the Gallican Churches”, the letter was sent to the churches of the mother country in Asia and Phrygia where there were strong, established connections and a synonymous Greek heritage.
The text was preserved for posterity by Eusebius of Caesarea in his Church History. It has been described as “the fullest description of early Christian martyrs”, and accordingly provides an excellent backdrop for examining and understanding the testimony and witness of suffering and martyrdom, which has application for the ongoing suffering of Christ’s church and its people.
However in 177 the Rhone valley was almost certainly a stronghold of the Cathar faith, not the Church of Rome. Marcus Aurelius almost certainly had nothing to do with this. His writings show him to be a man of wide religious tolerance. There were no church leaders, bishops or even priests who suffered the persecution, and the ” Epistle of the Gallician churches” was addressed not to Rome but to central Anatolia, where the alternate faith was also strong.
The Church of Rome subsequently claimed these martyrs as its own but they were in fact Cathars persecuted at the whim of a local governor with at least the compliance of the Church of Rome.
Decius
In January of AD 250 the emperor Decius demanded that all inhabitants of the empire should make a sacrifice to the ancestral gods. It is uncertain wether Decius intended to flush out Christians by this demand, but that is certainly the effect it had. Severe penalties were specified for those who did not comply. Pope Fabian was reportedly executed for refusing to make the sacrifice but many other christians, even bishops complied.
Diocletian
In AD 303 the Emperor Diocletian repeated the decree of Decius but applied it more forcibly. The persecution lasted over ten years and it was this persecution which inflicted the most damage to the christian community. The persecution was confined to the eastern provinces and was eventually ended by Constantine. A group known as the “Donatists” would not accept anyone who had made the sacrifice back into the church. Constantine eventually sided with the Donatists. This piece of information comes without any information comes to us without any comment on how it affected his relationship with the mainstream Church of Rome, who’s numbers presumably included large numbers who had sacrificed to the ancient gods.
Their is no doubt that members of the Church of Rome suffered at various times during the Roman Empire. Perhaps it was because of this that The church learned to be Ruthless in its elimination of any who had beliefs which were different to their own dogma.
Cathars, Celtic Christians, Orthodox Christians, Jews and dozens of minor sects were all targetted and opposition crushed using whatever force was necessary.