Galerius publishes his edict that begins the persecution of Christians in his portion of the Roman Empire.
The Diocletianic or Great Persecution was the last and most severe persecution of Christians in the Roman Empire. In 303, the emperors Diocletian, Maximian, Galerius, and Constantius issued a series of edicts rescinding Christians' legal rights and demanding that they comply with traditional religious practices. Later edicts targeted the clergy and demanded universal sacrifice, ordering all inhabitants to sacrifice to the gods. The persecution varied in intensity across the empireweakest in Gaul and Britain, where only the first edict was applied, and strongest in the Eastern provinces. Persecutory laws were nullified by different emperors (Galerius with the Edict of Serdica in 311) at different times, but Constantine and Licinius' Edict of Milan (313) has traditionally marked the end of the persecution.
Christians had been subject to intermittent local discrimination in the empire, but emperors prior to Diocletian were reluctant to issue general laws against the religious group. In the 250s, under the reigns of Decius and Valerian, Roman subjects including Christians were compelled to sacrifice to Roman gods or face imprisonment and execution, but there is no evidence that these edicts were specifically intended to attack Christianity. After Gallienus's accession in 260, these laws went into abeyance. Diocletian's assumption of power in 284 did not mark an immediate reversal of imperial inattention to Christianity, but it did herald a gradual shift in official attitudes toward religious minorities. In the first fifteen years of his rule, Diocletian purged the army of Christians, condemned Manicheans to death, and surrounded himself with public opponents of Christianity. Diocletian's preference for activist government, combined with his self-image as a restorer of past Roman glory, foreboded the most pervasive persecution in Roman history. In the winter of 302, Galerius urged Diocletian to begin a general persecution of the Christians. Diocletian was wary, and asked the oracle of Apollo at Didyma for guidance. The oracle's reply was read as an endorsement of Galerius's position, and a general persecution was called on February 23, 303.
Persecutory policies varied in intensity across the empire. Whereas Galerius and Diocletian were avid persecutors, Constantius was unenthusiastic. Later persecutory edicts, including the calls for universal sacrifice, were not applied in his domain. His son, Constantine, on taking the imperial office in 306, restored Christians to full legal equality and returned property that had been confiscated during the persecution. In Italy in 306, the usurper Maxentius ousted Maximian's successor Severus, promising full religious toleration. Galerius ended the persecution in the East in 311, but it was resumed in Egypt, Palestine, and Asia Minor by his successor, Maximinus. Constantine and Licinius, Severus's successor, signed the Edict of Milan in 313, which offered a more comprehensive acceptance of Christianity than Galerius's edict had provided. Licinius ousted Maximinus in 313, bringing an end to persecution in the East.
The persecution failed to check the rise of the Church. By 324, Constantine was sole ruler of the empire, and Christianity had become his favored religion. Although the persecution resulted in death, torture, imprisonment, or dislocation for many Christians, the majority of the empire's Christians avoided punishment. The persecution did, however, cause many churches to split between those who had complied with imperial authority (the traditores), and those who had remained "pure". Certain schisms, like those of the Donatists in North Africa and the Melitians in Egypt, persisted long after the persecutions. The Donatists would not be reconciled to the Church until after 411. Some historians consider that, in the centuries that followed the persecutory era, Christians created a "cult of the martyrs", and exaggerated the barbarity of the persecutions. Other historians using texts and archeological evidence from the period assert that this position is in error. Christian accounts were criticized during the Enlightenment and afterwards, most notably by Edward Gibbon. This can be attributed to the political anticlerical, and secular tenor of that period. Modern historians, such as G. E. M. de Ste. Croix, have attempted to determine whether Christian sources exaggerated the scope of the Diocletianic persecution, but disagreements continue.
Gaius Galerius Valerius Maximianus (; c. 258 – May 311) was Roman emperor from 305 to 311. During his reign he campaigned, aided by Diocletian, against the Sassanid Empire, sacking their capital Ctesiphon in 299. He also campaigned across the Danube against the Carpi, defeating them in 297 and 300. Although he was a staunch opponent of Christianity, Galerius ended the Diocletianic Persecution when he issued an Edict of Toleration in Serdica in 311. He was also famous for being very much tall and possessing a vigorous built, It is said that he kept bears as pets and matched them in both size and ferocity.