Final answer:
The first imperial episode of Christian persecution occurred during the reign of Emperor Nero in AD 64. The most widespread and official persecution was carried out by Diocletian in 303. The persecution of Christians ended under the rule of Emperor Constantine with the Edict of Milan in 313.
Step-by-step explanation:
The first recorded official persecution of Christians on behalf of the Roman Empire was in AD 64, when Emperor Nero attempted to blame Christians for the Great Fire of Rome. This was the first imperial episode of Christian persecution. Nero ordered the arrest and execution of many Christians, and they were also blamed for other problems in society.
Another notable period of persecution was during the rule of Diocletian, beginning in 303. During this time, Christians were arrested, tortured, and executed. The Great Persecution officially ended in 311.
It was not until the reign of Emperor Constantine that the persecution of Christians ended. Constantine issued the Edict of Milan in 313, which granted religious toleration to Christians and marked a significant turning point.