The first truly organised persecution of Christians came after the Great Fire of Rome in 64 AD under the Emperor Nero. Looking for a scapegoat in the devastating aftermath of the fire, he found it in the Christians.
He would blame them for the fire because of their apocalyptic belief that Rome and the world would end by fire. This led to an active and organised campaign against them. The second and third centuries sporadically saw more of the same prosecutions, especially under the reign of Emperors Decius and Valerian. The last and truly terrible persecution of Christians occurred at the beginning of the fourth century. A general edict of persecution, under the authority of Emperor Diocletian, was published on February 24th, 303 AD. Interestingly, on the day before the edict was published, Diocletian ordered the new Church at Nicomedia to be demolished. It was meant to signal the beginning of the end of Christianity for once and for all. Diocletian was inspired by his predecessor’s attempts to wipe out the Christians because they refused to offer up prayers to the pagan gods of Rome, which was something that was required by all the subjects of the empire. Diocletian supposedly also feared that the Roman gods had gone silent because of the disobedience of the Christians for putting their faith in only one god.
So began the ‘Great Persecutions’ as Bishops were imprisoned and tortured, in the general hope that they would renounce their belief in their god and return to the established practice of pagan worship. This edict or order was extended to the general Christian population too. Subsequently there were many deaths because Christians simply refused to renounce their faith in Jesus Christ. As part of the persecutions, churches and martyrs tombs desecrated and destroyed including Christian scriptures.
When Diocletian abdicated his throne in 305, his junior emperor Galerius, carried on with the persecutions with furious brutality for another six years. (It is important to note that the western half of the Roman Empire was largely unaffected by the persecutions because Emperor Constantius I and later his son, Constantine, had no enthusiasm to belittle or persecute the Christians.) By 311, Galerius officially finally put an end to the persecutions. Coincidentally, the end of the persecutions came at a time when he was serious ill, and he feared his illness was punishment inflicted on him by the Christian God. Christians were therefore once again allowed to worship their god. Scarcely two years later in 313, in a joint statement between Constantine and Licinius, Christianity would be placed on an equal footing with all other pagan religions of the empire.