The persecution of Christians by Diocletian began in 303 C.E. at a time when the Roman Empire was under extreme economic pressure. The economy of currency had been ruined and the tax system had to be based on payments in kind, just as the military were also paid in kind. Certain occupations that were considered to be essential for the maintenance of the Empire became known as ‘compulsory services’ and those engaged in them were prohibited from changing them. To try and unify the Empire at this politically difficult time, Diocletian used the state religion.

Diocletian had divided the Empire into four princeps to be run by four emperors. In 293 C.E. he appointed Galerius to the eastern empire of the Balkans. Galerius married Diocletian’s daughter Valerian who, along with her mother, was a Christian. It is considered by Eusibius that it was Galerian, at the behest of his mother, who instigated Diocletian to carry out persecutions of the Christians. Eusibius goes on to state that Diocletian thought that it would be foolish to have so many put to death, especially seeing that the Christians were eager to be martyred. Diocletian suggested that it would be enough to exclude Christians from court. However, he had many advisors who thought that Christians should be cut off ‘as enemies of the gods and adversaries of the established religious ceremonies’.

They began in the March 305 C.E. with the destruction of the church in Nicodemia, and the next day an edict was published that deprived Christians of all honours and dignities, that they would undergo torture, that all lawsuits against them would be accepted, that they could not be a plaintiff, and finally that they should not be free or have suffrage. Diocletian’s wife, Priscia, and Valeria were forced to sacrifice to the gods. Presbyters and officers of the church, along with their families, were seized without trial and executed by being burnt alive. The judges were dispersed to all the temples to compel everyone to sacrifice. Eusibius writes that the prisons became crowded and that the courts were set with alters so that every accused could turn and sacrifice. All the other emperors followed suit except for the emperor Constantinus, who only called for the demolition of churches.

In 305 Diocletian abdicated along with the second emperor Maximianus. Constantinus and Galerius became the new Augusti. Under Galerius the persecutions worsened, he began a mode of executions by edicts against the Christians, who were slowly and tortuously burnt to death. This punishment along with others became normal for all people. Under Galerius people were burnt, crucified and killed by wild beasts daily. Eusibius writes that this eventuated in a general illiteracy, with lawyers slain or exiled and the use of writing to be considered the same as magical or forbidden arts. All those who possessed books were considered enemies of the government and, once the law was dissolved, licence to be a judge was given to any rude and illiterate men.

Eusibius writes that the worst calamity to beset the Empire was the imposition of a capitation tax on all provinces and cities, where marketplaces were assembled with all the people, and sons hung on the rack to determine the effects of the fathers. Imaginary effects, the result of attestation through torture, were recorded on the lists. This infliction of all the subjects of Rome led to the number of animals decreasing and men dying. Eusibius goes on that all that was left were beggars and even they were rounded up and drowned in the sea. Constantinus in the meantime gave his sovereignty to his son Constantine in 306 C.E., much to the grief of Galerius.

By 312 C.E. Constantine was made the sole ruler of the Western Empire after the Battle of the Milvian Bridge. Lactantius, who was the tutor of Constantine’s son and close to the imperial family, reports that Constantine was commanded in a dream to place the sign of Christ on the shields of his soldiers. From that day Constantine identified himself as a Christian. Galerius had died the previous year after a terrible disease that, Eusibius writes, ate away his insides. Before he died, Galerius issued an Edict of Toleration which stated that because Christians in great numbers still persisted in their opinions, even after many were persecuted, they were permitted to worship their god and restore their places of worship. After Galerius’s death, Maximinius Daia proclaimed himself emperor of the east and continued the persecution of Christians in his realm.

In February 313C.E. Licinius, one of the emperors of the Eastern Empire met Constantine and formed a common religious policy. Although at that time Licinius issued an edict of toleration, he went on later to persecute Christians. Constantine, however, decided to use the church as an instrument of imperial policy and thus deprived it of its former independence. The church fathers throughout the Diocletian persecutions had struggled to maintain some control of their ‘flock’. This is attested to in a letter from four Egyptian bishops who questioned the bishop Melitius of Lycopolis and his authority to ordain priests. This caused a schism in which Peter of Alexandria wrote to his flock that ‘Miletius acts in no way for the common good’. This seems to imply that the martyrdom of many church leaders during the Diocletian persecutions was causing leadership stress within the church.

Constantine was dismayed when he discovered the disunity within the church, specifically in the province of Africa where there was conflict between the rigorist position towards the lapsi, those who had succumbed to the demand to sacrifice, and those who had a more forgiving position. Constantine convened two councils of bishops in 313 and 314 to resolve this problem unsuccessfully. The rigorists, under Caecilian bishop of Carthage, established a separatist church in North Africa. By 324 Constantine was the sole ruler in the Empire and wanted to to reconcile differences in beliefs about the Holy Trinity through convening the First Ecumenical Council of the church in 325. This was also unsuccessful. Eusibius eventually became the emperor’s chief spiritual advisor in 327. In 330 Constantine’s desire to have Byzantium become the new capital of Rome was realised. Here, he had built three major churches and made New Rome, unlike the pagan Old Rome, be a Christian capital.

It could be said that the effects of the persecutions on Christianity were the instigation of a Christian emperor and the ceding of much authority to him through a level of disunity among the bishops over key issues of forgiveness of the lapsi and beliefs about the Holy Spirit which resulted in breakaway churches.