Based on only the stories I've heard, and taking into account the fact that many are likely mythical (and ignoring the 1970s X-rated film I've heard about but never seen), for just all-around general craziness and badness, Caligula gets my vote. Besides, it gives me a chance to post this one of my "bygones" again:
Incredible topic and excellent posts by all. How does one measure evil? Total evil Deeds over time or single worst acts over motive? As was said above and written into history, Julius Caesar was responsible for the death of a million people in his military and political life. But my money is on Caesar Augustus. He had many heinous acts of cruelty attached to his name, IE, Proscription of the richest and most prominent people during the 2nd Triumvirate, eliminating all of their enemies and most importantly because they needed the money! He had Cesarean strangled to remove the threat against his claim to his name among many others family murders. After 40 years of power I am sure he purged as many of the history books as he could to control the narrative of his legacy as did many of the emperors in their time. Reading Cicero's orations, Suetonius's masterwork, Fragments of Livy, Pliny and Plutarch gives me the impression Octavian -Divus Caesar Augustus had to be totally and consciously evil to achieve and maintain the reins of absolute power -at any cost. No mental illness, no reservations about what had to be done to achieve his goals. He was a historic and original Evil political genius. He was able to gloss over his acts with a balance of good deeds and projecting absolute fear into everyone around him. He created an allusion of who he was and the people loved him regardless of how he came to power.
I am not nearly as harsh or hostile toward Caesar Augustus. I have been educating myself about the Roman emperors and the British kings and queens. One of the messages that comes out loud and clear from those studies is that, as the late Leo Durocher put it, “Nice Guys Finish Last” or in Rome, dead. Unlike the nice, clean transfers of power that we Americans and much of the civilized world have become accustomed to, Roman rulers had a choice. You either liquidated those who violently opposed you, or they liquidated you. From what I’ve read about Caesar Augustus, he had a long and prosperous rule that brought peace, prosperity and importantly, stability, to Rome. He set a standard for the emperors who would follow him. When he died, at the ripe age of 77, there was genuine sadness that he had passed. One of the errors that many young people make when they are evaluating the performances of historical figures is that you can’t take people out of the context of their times. While some of the things that Caesar Augustus and other affective leaders did might look cruel and even barbaric to us today, they had to deal with the mores of their time. When I was in undergraduate school in the late 1960s and early ‘70s, some college radicals dumped on Abraham Lincoln. Even the in Broadway musical “Hair,” he was the “mother f**king freer of the slaves.” What those young critics didn’t realize, or perhaps acknowledge, was that Lincoln was trying to win the war and restore the Union. If he had failed in that, the slaves would have been in bondage for even longer. Some people say that slavery could have survived until 1900. Sometimes he had to delay actions, like the Emancipation Proclamation, until the political climate was right. What looks right and easy to the casual observers today was anything but that in 1862.
I would say that the word for Octavian Augustus was not that he was 'immora'l but that he had no morals, hence 'amoral' being operating word.
None of these people had Christian values, and the Jewish people were the enemy. Octavian Augustus died in 14 AD. Jesus was, well 14, and was 16 years away from beginning his ministry. There is something to be said for Judeo - Christian values.
I'll not argue that point but Constantine and Constantius sure did not allow any Christian scruples to interfere with killing off members of the family
For sheer sexual perversion, Elagabalus gets my vote. Elagabalus (Augustus) Coin: Bronze As IMP CAES M AVR ANTONINVS PIVS AVG - Bust of Elagabalus, horned, laureate, draped, cuirassed, right. PM TR P IIII COS III PP S C - Elagabalus, in Syrian priestly robes, standing right, sacrificing out of patera in right hand over lighted altar, holding club in left hand; behind altar, bull crouching; something in field, star Exergue: Mint: Rome (221 AD) Wt./Size/Axis: 12.13g / 24mm / 12h Rarity: Rare References: RIC IV 325 Sear 7611 Provenances: London Ancient Coins (LAC) Acquisition/Sale: London Ancient Coins (LAC) VCoins $0.00 12/19 Notes: Dec 9, 19 - The Gary R. Wilson Collection Temple of Elagabalus