The Roman Empire had it share of Caesars who had serious mental conditions, but it was the duty of the Praetorian Guard to corner the really insane, and somehow, exit from a closed chamber with a call going out for a new Caesar.
Caligula comes to mind. Tiberius was the ultimate “dirty old man”. Nero had a blood-lust with his first two wives, killing and beheading the first, and kicking the second one to death. Nero replaced her with a young male whom Nero had castrated and turned into a transvestite, and there are also stories about a carnal relationship with his own mother. Commodus was a megalomaniac, competing in gladiatorial contests, posing as Hercules, and even, for a short while, had the City of Rome renamed after himself. And as a precursor of the present day mania for “transgenderism”, Elagabalus became ruler at age 14, changed the religion of Rome to animal sacrifice, and demoted even Jupiter to a secondary position among the gods, indulged in “experimental” sex, and even compelled his physicians to castrate him and give him female organs. Not much under the sun is that new or original.
How’d ‘dat all work out for ‘em?... Don’t just leave us hanging.
Also reminded of the late Merovingian monarchs, “Les rois faineants”, who were ineffectual figureheads while the real power was exercised by the mayors of the palace, the most famous being Charles Martel.