Episode 97of Mike Duncan's excellent History of Rome podcast deals with the depraved final years of the emperor Commodus (best known as Russell Crowe's nemesis in the Ridley Scott film Gladiator).
Here's a sample:
"Obviously you can’t have the emperor going out there and getting killed by some random slave, so Commodus typically fought pre-wounded opponents or, more commonly, opponents who had been given a lead sword to match up against the emperor’s sharpened steel ... Adding a malevolent edge to his somewhat ridiculous displays of alleged gladiatorial prowess was the fact that Commodus took particular delight in killing anything that seemed freakish. He would bring in midgets so he could pretend to be a mighty giant, he would bring in amputees and watch them hobble around feebly as he toyed with them, and at times he would put his surgical skills to the test and slowly dismember victims while avoiding major arteries."
"By 191, Commodus was beginning to lose touch even with the masses, who had always supported an emperor as obsessed with the games as they were. They began to look sideways at his obsession with Hercules, and took as mighty impious the claim that he was actually the reincarnation of the old Greek hero. When Commodus began erecting statues across the city featuring himself dressed as Hercules, and began carrying around a great big club which he called the 'Club of Hercules,' the people joined in the aristocracy’s concern over the sanity of their emperor."
"In early 192, he fully embraced his own outsized megalomania and declared that henceforth Rome would no longer be called 'Rome' but instead the 'Colonia Annia Commodiana,' in other words, 'The City of Commodus.' He further decreed that the 'legions' would now be called the 'commodiani,' and the 'Senate' would be called 'Commodus’s Fortunate Senate,' a sort of darkly comic re-branding. Having already changed his full name to 'Lucius Aelius Aurelius Commodus Augustus Herculus Romanus Exsuperatorius Amazonius Invictus Felix Pius,' he then changed the names of the months so that each lined up with one of his twelve corresponding names."