Which emperor blamed Christians for setting fire to Rome?

It was alleged that the fire of 64 AD was caused by emperor Nero wanted to burn down Rome to make room to build his massive palace The Golden House, Domus Aurea) by writers who were hostile to him. There is not any actual proof that he did this. Fires in Rome were very common as it was an overcrowded city and timber was used to build houses, which were packed in alleys. There were other large fired in 69 and 80 AD. Tacitus, a historian who lived during this period and the only one who gave details of the fire, did not suggest that Nero was an arsonist. He also said that Nero made great efforts to help the people affected by the fire. He spent days searching for survivors without bodyguards, opened his palaces to host the homeless and bought food supplies with his money. He then made an urban plan with houses built with brick, on wider roads and faced by porticoes. Another contemporary historian mentions the fire only in passing and three other contemporary writers did not mention it in their surviving work.

Suetonius, who was not even born at the time of the fire, and Cassius Dio, who lived about 100 years after the episode, alleged that Nero set Rome alight. According to one legend Nero played the fiddle during the fire. However, the fiddle did not exist in Nero's time.