28. Nero (Roman Empire)
Nero was one of the most ruthless Roman emperors. He reigned from 54 AD to 68 AD. He had a huge appetite for murder and debauchery, even had his own mother and wife killed. Among his atrocities was the persecution of the Christians. He would throw them alive into arenas to be fed to lions for entertainment. His reign ended in 68 AD when he took his own life to avoid arrest and execution.
