It has long been believed indeed that syphilis came from the Americas, but this theory is now disputed, in particular in the light of the finding of skeletons dating back from the middle-ages or even the antiquity with deformations normally associated with the last stages of syphilis.
'Specially since the fiddle hadn’t been invented yet. 
Ah yes. Caligula and Nero. The only two emperors directly descended from the Divine Augustus. The end-beat-all argument against hereditary monarchy, as far as I’m concerned.
On the surface, there are many similarities between the two. Both were overindulged, spoiled brats with delusions of grandeur. Both had violent tempers and had a tendency to kill (or order killed) those they saw as a potential threat, including members of their own families. Both were able to stay in power for as long as they did because of the effective bureaucracy set into motion by their predecessors, which allowed the daily business of government to grind on even when the central figure of power proved incapable of playing his designated role. In the end, both were overthrown violently.
As to which was worse, I’d say Caligula by a considerable margin. While both were raised in the corridors of power and preceded in their respective principates by capable administrators, Nero at least displayed some sense that he’d gained more from the experience than an exaggerated sense of self-worth. It also helps that he was sane. And no, BTW, he was not to blame for the fire. That so many people still believe him guilty demonstrates the longevity of conspiracy theories, though.
Worse as person- Caligula, Worse as Emperor- Nero. He brought Rome to civil war, and got immortalized as The Beast 666 by John of Patmos.
Incidentally, there may be a veiled reference to Caligula in Paul’s II Thessalonians 2, in which he refers to the Man of Sin who will enthrone himself in the Temple as God, but is held back by God’s restraining force. Well, before his assassination, Caligula planned to have a statue of himself installed in the Temple. And the Latin word for “Restraint”- claudere, the root for Claudius. And with Claudius’ murder, in came Nero, who launched the war on Judea which ended (after his death) with the destruction of the Temple, Jerusalem & the whole Priestly system.
I’m sorry if I just have to comment.
I know this is rather late.
But this thread is the very reason why I found out about this FORUM.
I was listening to an audiobook about the ROMAN EMPIRE and it piqued my interest.
And more importantly, I loved what I saw in this forum.
My take is: I’d have to vote for CALIGULA.
Though he was schooled by TIBERIUS in the fine arts of debauchery and power, he pushed the envelope further and created the TEMPLATE that would be emulated by every emperor next to him.
He is the Michael Jordan of the NBA. Though in a negative sense.
Nero himself is direct descendant of Caligula.
Though Caligula did not use fire, and cannot be charged with arsony (joke) he set the DIRECTION by which those after him would follow.
And yes, He did not try to have sex with his sister, he actually did.
He did not try to be deified, he claimed Godhood.
He did not try to hide his power, he flaunted it like an asset.
Thanks and Many may I post my 1,000th post here in time.
I too believe that Nero was unjustly maligned…but Caligula probably was seriously crazy. As for the Roman Imperial system-yes, the way emperors got selected was pretty bad. Still, the system held for nearly 500 years (reckoning from the end of the republic to the fall of Rome.)
I am more interested in the later emperors-many of them worked hard to protect the empire, but none of them were able to force the essential reforms that might have saved Rome. For example, emperor Diocletian-he tried to halt the insidious inflation that was wrecking the financial system-but his “cure” (rigid wage and price controls) was worse than the disease. In the end, the whole thing was unsustainable, because it depended upon continual conquest…and once that ended (under Trajan), it began an inevitable decline For example, Brittannia was abandoned in the late 5th century-because the financial resources to maintain two legions there did not exist.