The Roman Civil Wars of the 3rd and 4th Centuries: The History of the Conflicts that Led to a Split of the Roman Empire

The 50 years following the assassination of Severus Alexander on March 19, 235 CE has been generally regarded by academics as one of the lowest points in the history of the Roman Empire. This stands in stark contrast to the previous 150 years, which included the reigns of the Five Good Emperors and has been universally praised as one of the high points of the empire. Severus Alexander was the last of the Severan emperors, and the subsequent years of crisis (235-285 CE) were characterized by a series of short reigns, usually ending in the violent death of the reigning emperor.

At the same time, this period of time also saw the empire beset by threatening forces on all sides. The Romans faced a newly resurgent Persia in the east, as well as significant forces from German tribes on the Rhine and Goths along the Danube. The various conflicts would result in the unprecedented death of a sitting emperor in battle, which took place in 251 with Emperor Decius, and Emperor Valerian was captured in 260 CE.

Diocletian's reign would see reforms put into place to achieve the desired end of the Imperial Crisis, and several of the emperors before him may well have had the ability to manage the reform process, but the army’s power and willingness to use and abuse power ensured that few of them truly had a chance to really make their marks. It was the worst period in the history of the Roman Empire to that point, even as it forced the Romans to deal with belligerent foreign powers and problems created by the emergence of increasingly powerful and populous provinces.

As Roman leaders vied with each other for power and constantly fought civil wars, Rome’s famous roads fall into disrepair, the economy was crippled, the continent-wide trade system that had flourished in the previous years was replaced with a basic barter system, and there was a reduction in international trade. People became ever more fearful for their personal safety, and the Imperial Crisis saw an increasing trend toward sacrificing personal liberties and rights in return for guarantees of safety from wealthy landowners. All of this foreshadowed the emergence of the European feudal system and serfdom.

These were obviously turbulent times, and given the volatility, many historians have debated how the Roman Empire managed to survive in any form at all, let alone remain robust enough to allow Diocletian and his successors to restore it. Given the many people involved, and the relatively short era in which everything transpired, Rome’s Imperial Crisis has been difficult for historians to summarize, which is why, despite being one of the most intriguing periods in Roman history, it is often overlooked by people who have chosen to focus on the more cohesive periods before and after it.

At the same time, the fighting would bring about 4th century Rome’s most important leader, and one of the most consequential men of antiquity: Constantine the Great. He achieved enduring fame by being the first Roman emperor to personally convert to Christianity, and for his notorious Edict of Milan, the imperial decree which legalized the worship of Christ and promoted religious freedom throughout the empire. More than 1500 years after Constantine’s death, Abdu'l-Bahá, the head of the Bahá'í Faith, wrote, “His blessed name shines out across the dawn of history like the morning star, and his rank and fame among the world's noblest and most highly civilized is still on the tongues of Christians of all denominations.”

However, it can be argued that despite his military successes – the most notable of which occurred fighting for supremacy against other Romans – Constantine may well have set the stage for the ultimate collapse of the Roman Empire as it had existed up until that point.