An emperor being full of himself is hardly uncommon, but Commodus took it leaps and bounds too far. 

This bust of Commodus as Hercules was only one of many artistic depictions of the emperor cosplaying as the famous demi-god. He put up statues all over the city, even remodeling the Colossus of Nero into himself as Hercules. We can’t say for sure how many busts or statues were actually made, since most were destroyed - or re-edited in the instance of the Colossus -  in an attempt to erase his memory after his death. He might have pretended to be Hercules, but he was never anywhere near as likable or popular. This bust managed to survive the Commodus purge because it was hidden in an underground chamber until being discovered in 1874. Whether it was preserved for the sake of its subject matter or artistic merit is unknown. I’d wager the latter. 

Commodus was obsessed with this ideal of himself as Hercules, and I mean obsessed. He didn’t just have busts, coins, and statues made of the depiction; he actually went around wearing a lion cloak and carrying a club. Nowadays when we think of Hercules iconography, our minds might drift to the gladiator sandals and headband sported by the Disney hero, but back in the Ancient Roman days it was all about the lion cloak. 

This bust in particular seemed to stuff in as many heroic symbols as it could. There's the cloak and the club, but then he’s also holding the golden apples of the Hesperides. Since that apparently wasn’t enough to stroke his ego there’s also an Amazon kneeling to him (there were two for symmetry but only one survives). There’s also signs of the zodiac and an Amazonian shield.

Commodus’s lion cloak was just an ordinary lion skin obviously, nothing like the impenetrable skin of the Nemean lion that Hercules killed. But that didn’t stop Commodus from buying into his own propaganda. He actually started to believe he was Hercules. A cult spawned to worship him as Hercules, the coins of himself he had minted had “Hercules Commodianus” printed on them, and he ordered the senate to declare him a living god.

If you're not getting the picture, Commodus was a total egomaniac. He changed the calendar and renamed all the months after himself. He renamed the city of Rome itself “Colonia Lucia Aelia Nova Commodiana” which roughly translates to “The New Colony of Commodus” or, basically, “city of me”. He even renamed the senate “The Lucky Commodian Senate." There weren’t any Romans anymore; they were all now “Commodian people." I’m sure you can imagine why he wasn’t well-liked, but apparently the common people got a kick out of all his antics.

There are a few similarities between Commodus and Hercules. One being madness (though for Hercules it was temporary from a goddess’s curse), and another being a violent temper. When Hercules was young, he killed his music tutor after the tutor insulted him. When Commodus was eleven, he ordered the man who poured his bath to be thrown into a furnace because the water wasn’t hot enough. Luckily for that man, they threw a sheepskin in the furnace instead, and Commodus couldn’t tell the difference. 

Now, just because Commodus was clearly insane and paranoid doesn’t mean there weren’t several conspiracies plotted against him and attempts on his life. In one instance, his sister’s son was to stab him to death, and he probably would have succeeded if he hadn’t made the mistake of shouting out his intention before doing the deed. Shouting dramatically before an attack really only works in the movies. 

Commodus also tended to rig things in his favor. He got into gladiator combat after adopting his Hercules persona, but in public battles the weapons would be blunted and the opponents physically handicapped. He did have a good crowd at these performances, mostly because he forced all senators and knights to attend. They were also ordered to chant loudly about how awesome he was. 

Eventually, his own ridiculousness caught up to him. In a plot against him, he was given poison before a bath. When the poison didn’t work, a wrestler named Narcissus (no relation to the reflection obsessed Greek) was sent in to strangle him to death. Concrete proof he was not Hercules. Had it been Hercules, the attempt would have evolved into a wrestling match and led to another ill-fated Narcissus.