From The Nation review of Gladiator:
According to Gibbon, the emperor Commodus spent the early years of his reign "in a seraglio of three hundred beautiful women and as many boys, of every rank and of every province." Later, adding bloodshed to his round of pleasures, he launched a career in murder, beginning with the dispatch of the usual senators, ministers and family members and continuing with the slaughter of beasts. Styling himself the Roman Hercules, he went as a performer into the amphitheater, where he cut down before the public a number of ostriches, a panther, a hundred lions, an elephant, a rhinoceros and a giraffe. He then entered the lists as a gladiator. Commodus fought 735 times and paid himself such a high fee for each appearance that a new tax had to be levied. No harm came to him in the arena, if only because he furnished his opponents with weapons of lead; so it was left to Marcia, his favorite concubine, to rid Rome of Commodus. One night, aided by a chamberlain and the Praetorian prefect, she admitted a professional wrestler to his bedchamber to strangle him as he lay in a drunken stupor.
Marcus Aurelius Commodus Antoninus, the son of the Emperor Marcus Aurelius and his wife-cousin Faustina, was born in Lanuvium in 161 AD.
Commodus was named Caesar at the age of 5, and co-Augustus at the age of 17, spending most of his early life accompanying his father on his campaigns against the Quadi and the Marcomanni along the Danubian frontier. His father died, possibly of the plague, at a military encampment at Bononia on the Danube on 17 March 180, leaving the Roman Empire to his nineteen-year-old son. Upon hearing of his father's death, Commodus made preparations for Marcus' funeral, made concessions to the northern tribes, and made haste to return back to Rome in order to enjoy peace after nearly two decades of war.
Commodus, and much of the Roman army behind him, entered the capital on 22 October, 180 in a triumphal procession, receiving a hero's welcome. Indeed, the youthful Commodus must have appeared in the parade as an icon of new, happier days to come; his arrival sparked the highest hopes in the Roman people, who believed he would rule as his father had ruled.
The coins issued in his first year all display the triumphant general, a warrior in action who brought the spoils of victory to the citizens of Rome. There is a great deal of evidence to support the fact that Commodus was popular among many of the people, at least for a majority of his reign. He seems to have been quite generous. Coin types from around 183 onward often contain the legend, Munificentia Augusta, indicating that generosity was indeed a part of his imperial program. Coins show nine occasions on which Commodus gave largesses, seven when he was sole emperor.
According to Dio, the emperor obtained some of this funding by taxing members of the senatorial class. This policy of munificence certainly caused tensions between Commodus and the Senate. In 191 it was noted in the official Actus Urbis that the gods had given Commodus to Populus Senatusque Romanus. Normally the phrase Senatus Populusque Romanus was used.
While the Senate hated Commodus, the army and the lower classes loved him. Because of the bad relationship between the Senate and Commodus as well as a senatorial conspiracy, Rome "...was virtually governed by the praetorian prefects Perennis (182-185) and Cleander (186-9)."
Commodus began to dress like the god Hercules, wearing lion skins and carrying a club. Thus he appropriated the Antonines' traditional identification with Hercules, but even more aggressively. Commodus' complete identification with Hercules can be seen as an attempt to solidify his claim as new founder of Rome, which he now called the Colonia Lucia Annia Commodiana. This was legitimized by his direct link to Hercules, son of Father Jupiter. He probably took the title of Hercules officially some time before mid-September 192.
While the literary sources, especially Dio, Herodian, and the Historia Augusta, all ridicule the antics of his later career, they also give important insight into Commodus' relationship to the people.
His most important maneuver to solidify his claims as Hercules Romanus was to show himself as the god to the Roman people by taking part in spectacles in the amphitheater.
Not only would Commodus fight and defeat the most skilled gladiators, he would also test his talents by encountering the most ferocious of the beasts. Commodus won all of his bouts against the gladiators. The slayer of wild beasts, Hercules, was the mythical symbol of Commodus' rule, as protector of the Empire.
During his final years he declared that his age should be called the "Golden Age." He wanted all to revel in peace and happiness in his age of glory, praise the felicitas Commodi, the glorious libertas, his pietas, providentia, his victoria and virtus aeterna.
Commodus wanted there to be no doubt that this "Golden Age" had been achieved through his munificence as Nobilissimus Princeps. He had declared a brand new day in Rome, founding it anew in 190, declaring himself the new Romulus. Rome was now to be called Colonia Lucia Annia Commodiana, as noted above, and deemed "the Immortal," "the Fortunate," "the Universal Colony of the Earth." Coins represent the archaic rituals of city-[re]foundation, identifying Commodus as a new founder and his age as new days.
Also in 190 he renamed all the months to correspond exactly with his titles. From January, they run as follows: Lucius, Aelius, Aurelius, Commodus, Augustus, Herculeus, Romanus, Exsuperatorius, Amazonius, Invictus, Felix, Pius. According to Dio Cassius, the changing of the names of the months was all part of Commodus' megalomania. Commodus was the first and last in the Antonine dynasty to change the names of the months. The legions were renamed Commodianae, the fleet which imported grain from Africa was called Alexandria Commodiana Togata, the Senate was deemed the Commodian Fortunate Senate, his palace and the Roman people were all given the name Commodianus. The day that these new names were announced was also given a new title: Dies Commodianus. Indeed, the emperor presented himself with growing vigor as the center of Roman life and the fountainhead of religion. New expressions of old religious thought and new cults previously restricted to private worship invaded the highest level of imperial power.
If Eusebius of Caesarea is to be believed, the reign of Commodus inaugurated a period of numerous conversions to Christianity. Commodus did not pursue his father's prohibitions against the Christians, although he did not actually change their legal position. Rather, he relaxed persecutions, after minor efforts early in his reign.
Tradition credits Commodus's policy to the influence of his concubine Marcia; she was probably his favorite, but it is not clear that she was a Christian. More likely, Commodus preferred to neglect the sect, so that persecutions would not detract from his claims to be leading the Empire through a "Golden Age."
During his reign several attempts were made on Commodus' life. After a few botched efforts, an orchestrated plot was carried out early in December 192, apparently including his mistress Marcia. On 31 December an athlete named Narcissus strangled him in his bath, and the emperor's memory was cursed. This brought an end to the Antonine Dynasty.