Septimius Severus was finally appointed Caesar following the brief reigns of Pertinax, Julianus and Clodius Albinus (192 – 211). Edward Gibbon credits Severus as the first of the emperors of the decline of the Roman Empire. Appointed by the Praetorian Guard, he too was later to be assassinated by them. He had risen to power mainly as a result of having married well, although not well enough to remain alive for very long. He continued in power as long as he did by using the highly successful tactic of eliminating the opposition. Severus defeated Julianus and also an attempt by Pescennius Niger, Consul of Asia, to accede to the role of Caesar in Rome, who had in fact been granted the title Caesar over the eastern part of the empire.
During the reign of Severus the Roman government issued the first official edict of persecution against Christianity. This period is also when the Roman Empire was split into eastern and western camps with near continuous battles for control by the co-emperors and other contenders.
Caracalla (Lucius Septimius Bassianus) and his brother (Publius Septimius Geta) followed Severus and collectively ruled from 211 to 217. They actually came to be appointed co-emperors while their father Severus was still ruling, imposing three Caesars or Antonines on the empire for the first time. Caracalla was the first son of Severus and was only second behind him as a tyrant. Upon the death of Severus, Caracalla and Geta continued as co-emperors. This situation lasted until Caracalla had his brother killed by mercenaries, as they were to negotiate their territories and end the civil war that had surrounded their ambitions and scrabble for power. As with the others, martyrdoms continued under both and through the reign of Elagabalus, the eventual successor. Caracalla also had his mother Julia murdered. They were fine folks all.
In 217 Marcus Opellius Macrinus had been the head of the Praetorians under both Severus and Caracalla. Caracalla began plotting to kill him to secure the allegiance of the Praetorians, but word of the plot came to Macrinus by accident. He in turn had Caracalla murdered and then on the third day following had the Consul Adventus appointed emperor. Adventus, being somewhat brighter than most of his contemporaries, knew of Macrinus’s ambition and immediately abdicated in favor of the Praetorian, so quickly in fact, that the senate never actually confirmed him as emperor. Macrinus then immediately appointed his son, Marcus Opellius Antoninus Diadumenianus, Emperor and Antoninus (the favored title since the Antonines had ruled) although he remained the actual power within the empire. The reign of the son was nearly as short-lived as had been his father’s (twelve months and fourteen months), both ending in 218.
Both Macrinus and later Diadumenianus were murdered, and the Praetorians and the other co-conspirators wrongly identified Elagabalus or Heliogabalus (given name: Varius Avitus Bassus) as the son of Caracalla (whose reputation then seemed somehow redeemed). He was in fact a descendant of Severus’ wife’s sister and not a direct heir of either Severus or of Caracalla as based upon the then accepted although not usually followed lines of succession. That was all overlooked and he was enthroned in 218. He did not survive very long and was murdered in 222. This era, that of the Severan Emperors lasting from 192 and ending in 235 (with the exception of Alexander’s reign) was one of the worst periods of persecutions of Christians and also of general mayhem within the government of Rome.
Alexander Severus (Marcus Aurelius Severus Alexander, 222 — 235), last of the Severans, was an adopted son of Elagabalus and had been appointed Caesar by him. They had ruled jointly for a short time until Elagabalus was murdered. Alexander’s own rule was much longer and mostly peaceful, as unlike his father, his popularity with the Praetorians and the people both acted to protect and prolong his life. Upon his death Maximinus Thrax (Gaius Iulius Verus Maximinus) was briefly appointed emperor followed by his son Maximus as Caesar and finally by his son Balbinus also as Caesar. These were all murdered in various intrigues.
This period of upheavals and removals was followed by a worsening period of civil wars when emperors were typically put in place by the legions and also dispatched with equal swiftness. The more lengthy or notable reigns (if that can be said) were those of Philip, Decius, Gallus, Aemilianius, Valerian, Gallienus, Claudius of Pavia, Aurelian, Tacitus, Probus, Carus and his sons Carinus and Numerian. Of these mentioned, Philip, who reigned for seven years, was sympathetic to the Christians though in his successors Decius’ reign, he had the distinction of being the worst for persecutions during this period following the Severans and preceding that of the Gordians.
During this darkening period the Goths (at the time actually the Ostrogoths) first attacked the Roman Empire sacking Byzantium in 267 while Claudius of Pavia was emperor. There were no less than 20 emperors between 235 and 285 and 40 other men that each laid claim to the titles Caesar, Augustus or Antoninus at some point. There were also periods of near total collapse in the government.
Of these emperors several (such as Maximinus Thrax, Maximus, and the three Gordians beginning with Marcus Antonius Gordianus Sempronianus) persecuted Christians and entire communities were burned and destroyed. The persecutions included murdering church leaders, looting and burning public worship areas along with the confiscation or burning of private homes. These types of activities continued unabated into the fourth century.
The greatest persecution (the longest and most severe) occurred during the reign of Diocletian (Gaius Aurelius Valerius Diocletianus), even though he was generally considered a benevolent ruler. He ruled alone until his abdication in 305. The throne then was briefly held by yet another emperor named Severus, Flavius Valerius Severus, who ruled from 306 through 307. After that brief rule, the empire was no longer under an emperor or one Caesar each for east and west, but came under the rule of four titled Augusti and Caesari, one of these being Diocletian (Caesar along with Maximian – Marcus Aurelius Valerius Maximianus Herculius), another being his son Galerius Maximianus (Augustus along with Constantius Chlorus, the father of Constantine).
In 311, Galerius sought atonement for his and the persecutions of the others and issued the Edict of Toleration for Christianity, which was largely ignored in the empire until Constantine assumed the throne of Rome in 313.
Licinius (Flavius Galerius Valerius Licinianus Licinius) reigned with Maximinus Daia, as co-emperors following the rule of the two Caesari and two Augusti. He defeated Maximinus and later also served as co-regent with Constantine. A civil war erupted between the two (oddly enough over power). Constantine (a Greek name derived from the Latin word meaning constant or consistent), the first non-Latin named emperor, eventually defeated Licinius following yet another civil war.
Constantine was then named sole Imperator in 323 once again uniting the eastern and western empires under a single leader. Under Constantine the Edict of Toleration was reissued known as the Edict of Milan (324), and by 325 Christianity was granted recognition as religio licita and the persecutions of the Roman government officially and in fact ended.
Although Constantine the Great was considered the first Christian emperor, he was perhaps less a Christian than he was a smart politician and able ruler. He was capable of seeing the advancing value of the religion and thereby aligned his fortunes with it to the continuation of the faltering empire.
This concludes our little exercise in the history of Rome up through 325 AD. The Roman Empire continued on this path of decline until 476 when it finally collapsed from the external threat of invasion and the internal virus of corruption. It has been said that the spread of Christianity was in large part responsible for the collapse of the Roman Empire, and should you decide to research that thought, you might conclude that it is true (as the book of Revelation implies).