Commodus's sole reign is commonly thought to mark the end of a golden age of peace and prosperity in the history of the Roman Empire (the Pax Romana).

His solo reign saw less military conflict than that of Marcus Aurelius, but internal intrigues and conspiracies abounded, goading Commodus to an increasingly dictatorial style of leadership.

Whereas the reign of Marcus Aurelius had been marked by almost continuous warfare, Commodus' rule was comparatively peaceful in the military sense, but was also characterised by political strife and the increasingly arbitrary and capricious behaviour of the emperor himself.

The principal surviving literary sources are Herodian, Cassius Dio (a contemporary and sometimes first-hand observer and Senator during Commodus' reign, whose reports for this period survive only as fragments and abbreviations), and the Historia Augusta (untrustworthy because of its character as a work of literature rather than of history, with elements of fiction embedded within its biographies; in the case of Commodus, it probably embroiders what the author found in reasonably good contemporary sources).

Nevertheless, though the senatorial order came to hate and fear him, the evidence suggests he remained popular with the army and the common people for much of his reign, not least because of his lavish shows of largesse (recorded on his coinage) and because he staged and took part in spectacular gladiatorial combats.

On many inscriptions, the traditional order of the two nominal powers of the state, the Senate and People (Senatus Populusque Romanus) was provocatively reversed (Populus Senatusque...).

Lucilla's husband, Pompeianus, was not involved, but two men alleged to have been her lovers, Marcus Ummidius Quadratus Annianus (the consul of 167, also her first cousin) and Appius Claudius Quintianus, attempted to murder Commodus as he entered a theater.

After the murder of the powerful Saoterus, Perennis took over the reins of government and Commodus found a new chamberlain and favourite in Cleander, a Phrygian freedman who had married one of the emperor's mistresses, Demostratia.

War broke out in Dacia: few details are available, but it appears two future contenders for the throne, Clodius Albinus and Pescennius Niger, both distinguished themselves in the campaign.

Also, in Britain in 184, the governor Ulpius Marcellus re-advanced the Roman frontier northward to the Antonine Wall, but the legionaries revolted against his harsh discipline and acclaimed another legate, Priscus, as emperor.

In the spring of 190, Rome was afflicted by a food shortage, for which the praefectus annonae Papirius Dionysius, the official actually in charge of the grain supply, contrived to lay the blame on Cleander.

At the end of June, a mob demonstrated against Cleander during a horse race in the Circus Maximus: he sent the Praetorian Guard to put down the disturbances, but Pertinax, who was now City Prefect of Rome, dispatched the Vigiles Urbani to oppose them.

In AD 191, Commodus took more of the reins of power, though he continued to rule through a cabal consisting of Marcia, his new chamberlain Eclectus, and the new praetorian prefect Quintus Aemilius Laetus.

In opposition to the Senate, in his pronouncements and iconography, Commodus had always stressed his unique status as a source of god-like power, liberality, and physical prowess.

Far from celebrating his descent from Marcus Aurelius, the actual source of his power, he stressed his own personal uniqueness as the bringer of a new order, seeking to re-cast the empire in his own image.

Perhaps seeing this as an opportunity, early in 192 Commodus, declaring himself the new Romulus, ritually re-founded Rome, renaming the city Colonia Lucia Annia Commodiana.

All the months of the year were renamed to correspond exactly with his (now twelve) names: Lucius, Aelius, Aurelius, Commodus, Augustus, Herculeus, Romanus, Exsuperatorius, Amazonius, Invictus, Felix, and Pius.

He also had the head of the Colossus of Nero adjacent to the Colosseum replaced with his own portrait, gave it a club, placed a bronze lion at its feet to make it look like Hercules Romanus, and added an inscription boasting of being "the only left-handed fighter to conquer twelve times one thousand men".

[27] In November 192, Commodus held Plebeian Games, in which he shot hundreds of animals with arrows and javelins every morning, and fought as a gladiator every afternoon, winning all the fights.

[28] Upon his death, the Senate declared him a public enemy (a de facto damnatio memoriae) and restored the original name of the city of Rome and its institutions.

In 195, the emperor Septimius Severus, trying to gain favour with the family of Marcus Aurelius, rehabilitated Commodus' memory and had the Senate deify him.

His great simplicity, however, together with his cowardice, made him the slave of his companions, and it was through them that he at first, out of ignorance, missed the better life and then was led on into lustful and cruel habits, which soon became second nature.

[31] Another event, as recorded by the historian Aelius Lampridius, took place at the Roman baths at Terme Taurine, where the emperor had an attendant thrown into an oven after he had found his bathwater to be lukewarm.

[2] Later that year he adopted as his full style Lucius Aelius Aurelius Commodus Augustus Herculeus Romanus Exsuperatorius Amazonius Invictus Felix Pius (the order of some of these titles varies in the sources).

He thought of himself as the reincarnation of Hercules, frequently emulating the legendary hero's feats by appearing in the arena to fight a variety of wild animals.

[37] Cassius Dio and the writers of the Augustan History say that Commodus was a skilled archer, who could shoot the heads off ostriches in full gallop, and kill a panther as it attacked a victim in the arena.

[39] According to Herodian, spectators of Commodus thought it unbecoming of an emperor to take up arms in the amphitheater for sport when he could be campaigning against barbarians among other opponents of Rome.

[40] Popular rumors spread alleging he was not actually the son of Marcus Aurelius, but of a gladiator his mother Faustina had taken as a lover at the coastal resort of Caieta.

[41] Cassius Dio claimed that citizens of Rome who lacked feet (either through accident or illness) were taken to the arena, where they were tethered together for Commodus to club to death while pretending they were giants.

[45] Later, he decapitated a running ostrich with a specially designed dart[46] and afterward carried his sword and the bleeding head of the dead bird over to the Senators' seating area, and motioned to suggest that they were to be next.