They were persecuted under a few emperors. Nero was mentioned by Prof. Pagels. It was never widespread persecution the way the Church Fathers wrote and famous painting show. I did a college term paper on the Christian martyrs. Christians were tolerated for the most part. Local stressors, such as an economic downturn, might cause an outbreak of martyrdom. Ignatius begs Christians not to interfere. He wants to be eaten by hungry lions. The bad part for the church was that in some local areas your baptism date meant nothing. Your birthday in Christ was your martydom. Eager beavers would be tortured. It was a fad in the church. Under torture the eager ones divulged the names and addresses of other Christians not so eager. The Church decided to make martydom less attractive. The neutral accounts of witnesses were very moving. Christians would grab the bones from the street.
Christians were charged with crimes against the human race. Pagels writes that at some point Christians in several locations voluntarily stayed behind in plagues to help the sick and dispose of dead bodies with dignity. The pagans were impressed.