Diocletian chose to rule the eastern half of the Empire and appointed Galerius as his caesar. In the west, Diocletian’s friend Maximian was named augustus, with Constantius as his caesar. In order to further strengthen the tetrarchy and prevent civil war, Diocletian bolstered the political bond between the men through marriage. Constantius married Maximian’s daughter Fausta, and Galerius married Diocletian’s daughter Valeria. Additionally, each caesar was adopted by his augusti. Diocletian chose to make his imperial home in the city of Nicomedia and only visited the capital city of Rome once, during the celebration of his twentieth anniversary as emperor. Galerius, his caesar, resided in Sirmium (modern-day Serbia). In the west, Maximian made his residence in Milan, whereas Constantius lived in Trier (modern-day Germany). Rome, the ancient capital, was discarded as an imperial residence but retained influence due to its large population and the presence of the Senate.
Diocletian was tolerant of Christians for the first nineteen years of his reign, and there is speculation that members of his immediate family may have been Christian. Everything changed, however, when Galerius, known by one later Christian writer as “the Beast,” persuaded Diocletian to initiate what became known as the Great Persecution because of a military readiness problem in the eastern legions. Some Christians in the east refused military service, which was causing a manpower shortfall in the army. Christians who had joined the army refused to sacrifice to the pagan gods before battle (per army custom and tradition), which affected unit morale and cohesiveness. Galerius believed the issue in the army was a crisis, so he asked Diocletian to deal with the Church once and for all.
Diocletian issued the first edict of persecution on February 23, 303, ordering the closing of all known Christian churches and buildings. He demanded that all copies of the Scriptures be handed over to Roman authorities for destruction. Further edicts ordered first the imprisonment of the clergy, and then torture and execution of bishops, priests, and deacons. A final edict was passed that mimicked Decius’s general order in the previous century, requiring all Romans to sacrifice to the pagan gods. Persecution of the Church was widespread in the eastern half of the Empire, especially in North Africa (Egypt), where more than two hundred bishops were martyred. It was more sporadic in the west since the western emperor, Constantius, did not vigorously enforce the edicts.80
We have historical knowledge of the Great Persecution from three main sources: the writings of Eusebius of Caesarea and Lactantius (c. 250–c. 330), and the Acts of the Martyrs. Eusebius was an eyewitness to the persecutions in Palestine and Egypt. He wrote of the violence in his works Ecclesiastical History and The Martyrs of Palestine. Lactantius was a North African teacher of rhetoric who became the tutor to Constantine’s son Crispus. He wrote about the Great Persecution in his De mortibus persecutorum, positing the belief that emperors who persecuted the Church ended their lives in a violent and horrible fashion as punishment from God. The Acts of the Martyrs was a compilation of stories about the martyrs. Verbal transcripts of exchanges between arrested Christians and Roman officials, eyewitness accounts, and even imaginary narratives were utilized in crafting these works. These sources allowed later Christians to understand the ferocity unleashed by the Roman Empire on the Church in the early fourth century.
Christians who suffered through the Great Persecution were divided into groups, depending on how they responded during the crisis. Some refused to give in to the edicts requiring submission to the pagan gods and, as a result, were killed for the Faith. Known as martyrs (“witnesses”), these brave Christians suffered horrible deaths by fire, wild beasts, beheading, and other manners of painful death. Not every Christian arrested during the persecutions died, but many, known as the confessors, were imprisoned and suffered the tortures of racking, beating, scourging, or having their fingernails ripped out. Christian women were frequently sent to brothels. Men were oftentimes sent to the mines, where the tendon of their left foot was cauterized to prevent escape. Those who toiled in the mines also had their right eye ripped out, and the wound burned with a hot iron. Sometimes they suffered the horror of castration. Despite their harsh treatment, Christians in the mines (who were ministered to by clandestine aid from their brethren) continued to preach the Gospel and brought fellow prisoners to Christ. Unfortunately, under extreme stress, some Christians gave in to the dictates of the persecution edicts and apostatized. They were known as traditores (“traitors”) from the Latin tradere, “to hand over.” There were different classes of traditore — those who handed over copies of the sacred Scripture, those who handed over the sacred vessels used in the celebration of Mass, and those who revealed the names of Christians who had such items in their possession. The extensive destruction of copies of the Scriptures during the Great Persecution was remembered for centuries. Finally, some Christians, known as the lapsi, gave in during the persecutions and, after they ended, desired readmittance. The subsequent discussion of how to handle their request for return to communion dominated the early life of the Church, in essence centering on whether the Church was a “society of saints or a school for sinners.”81
The question of how to handle the lapsi was an issue after the first general persecution under Emperor Decius in the mid-third century. Pope Saint Cornelius (r. 251–253) believed it was his pastoral duty to restore to communion those who fell during the persecution. He thought their participation in the Eucharist, after a suitable period of penance, would strengthen them in the event of future attacks. Saint Cyprian (200–258), bishop of Carthage, also believed the Church should follow the road of mercy for the lapsi. During the Decian persecution, Cyprian had fled his see and was criticized for abandoning his flock. After the persecution ended, Cyprian focused on restoring unity in his diocese by urging mercy and patience, especially for the lapsi. He gathered fellow bishops in North Africa in a local council to discuss the lapsi. They decided that those who had received the libellus but did not personally sacrifice could be readmitted to communion after a period of penance. Those who had sacrificed were required to undertake a prolonged period of penance and could be reconciled on their deathbeds.82 When the persecution under Valerian began, Cyprian refused to leave Carthage and became the first African bishop martyred during the persecution. Both Cornelius and Cyprian imitated the Lord’s mercy in their dealings with the lapsi, and their example set the policy for the Church in later persecutions. Their emphasis on unity and mercy — as opposed to the rigorists, who wanted permanent expulsion of the lapsi — helped the Church settle this critical question. As a result, the Church honors their sanctity by a shared feast day (September 16) on the liturgical calendar.
The Great Persecution of Diocletian witnessed the martyrdoms of saints such as Agnes, a young virgin; Sebastian, a centurion; and Lucy, a young woman betrayed to the authorities by her betrothed. The killing was especially terrible in North Africa, where Eusebius recorded the extermination of entire towns populated by Christians. Indeed, he records that “so many were killed on a single day that the axe, blunted and worn out by the slaughter, was broken in pieces, while the exhausted executioners had to be periodically relieved.”83 The torments and methods of execution were horrific, as Eusebius describes in his Ecclesiastical History:
Immense numbers of men, women, and children, despising this transient life, faced death in all its forms for the sake of our Savior’s teaching. Some were scraped, racked, mercilessly flogged, subjected to countless other torments too terrible to describe in endless variety, and finally given to the flames; some were submerged in the sea; others cheerfully stretched out their necks to the headman’s axe; some died under torture; others were starved to death; others again were crucified, some as criminals usually are, some with still greater cruelty nailed the other way up, head down, and kept alive till they starved to death on the very cross.84
The Great Persecution ended because Diocletian wanted to retire to his cabbage farm in Dalmatia. He abdicated in 305, becoming the first emperor to voluntarily give up power. His caesar, Galerius, succeeded him