When Revelation was given to John all the apostles had been murdered because a shift occurred in Rome’s dealing with the Christians:
Christian History Issue 27 notes: “The persecutors and their motives changed in A.D. 64. On July 19 that year a great fire engulfed much of Rome; only four of the fourteen quarters of the city escaped damage. Suspicion immediately fell on Emperor Nero: was this a madcap way of clearing part of the city to make room for new, magnificent streets and buildings in his honor? Nero, however, managed to deflect blame first, apparently, on the Jews, who had a reputation for large-scale arson but also had friends at court; and then onto the Christians. Many Christians (perhaps including Peter) were seized, tortured, and done to death in the arena.” Tacitus, writing in 115 AD, included an account of the incident in his Annales (XV, 44). Except for the manner of the Christians’ deaths, which he thought excessively cruel, he showed no sympathy for the Christians.”
Nero was so relentless in killing Christians that it is said that at night he illuminated his gardens with the bodies of burning Christians on poles.
The Roman historian Tacitus said that Nero did not just put Christians to death he used their brutal deaths to amuse the Roman people at the circuses.