Bardy, G. (Trans. P.W. Singleton). "Chapter Six: Christianity and the Roman Empire at the End of the First Century." The Church at the End of the First Century. London: Sands & Co. 1938, 124-138.
The Roman Empire at first had no opinion specific to Christianity, but considered it as a sect of Judaism (Bardy 1938, 124). As late as about 51 or 52, Christianity was considered equivalent to Judaism (Acts 18:14-15). However, with the fire at Rome in July of 64, the Christians, not the Jews, were accused of starting the damage (Bardy 1938, 125). The extent of the Neronian persecution was long remembered as a great martyrdom for Christians. Bardy cites Clement's description of it, some thirty years after the fact (Bardy 1938, 126).
The Neronian persecution, though it didn't last long, betrays a philosophical concept of great importance. "Christianity was irreconcilable with contemporary ideas to as great an extent as it was with Roman legislation on religious matters. The ancient world admitted neither freedom of worship nor atheism" (Bardy 1938, 128). This prevented any accommodation. In Bardy's opinion, this problem is exemplified best by the evidence of Pliny's letter to Trajan, and by Trajan's answer (Bardy 1938, 130). Those who were accused and convicted were to be punished, but they should not be sought out. Tertullian understood this to be self-contradictory, as all other types of criminals are sought out (Bardy 1938, 131).
Between Nero and Trajan, we know of a persecution under Domitian, in which even some members of the imperial family were removed from society, along with the consul Clement in 95 (Bardy 1938, 132). John's Apocalypse, written about the same time, describes times of persecution and martyrdom (Bardy 1938, 133).
By the time of Trajan, Bardy finds there to be some relief from persecution. As evidence of this, he observes that Ignatius, rather than being summarily executed in Antioch, was transported to Rome (Bardy 1938, 136). In many areas there was relative peace.