Having covered Rome’s Golden Age and the chaotic succession of short-lived or tyrannical emperors during the 2nd and 3rd centuries AD in Part 1 (chapters 1-14), we now continue in Part 2 with the remainder of Volume I of Decline and Fall (chapters 15-26), describing the reign of Constantine the Great and his descendants, and the increasing importance of the Eastern Empire. Gibbon also spends several chapters devoted to the rise of Christianity, a religion initially persecuted in the first three centuries, but persisting and eventually rising to become a dominant cultural and religious force in the Empire. In this period, the cultural battle and interplay between Christianity and pagan religion is so prominent that it becomes a necessarily intertwined part of the general history of the empire. However, we shall postpone the narration of the rise of Christianity for a separate post.

The Reign of Constantine

The most visible legacy of Constantine’s reign was the founding of the city of Constantinople, which became the new capital of the empire. Initially, Constantine had secured his victory over his rivals through his quick movement and rapid response. This nimble reputation continued throughout his reign, as Constantine darted from one end of the empire to another, vanquishing both foreign enemies and internal rebellions. However, according to Gibbon, “as he gradually reached the summit of prosperity and the decline of life, he began to meditate the design of fixing in a more permanent station the strength as well as majesty of the throne” (Chapter XVII). Constantinople was distinguished as the first explicitly Christian city in the empire. Constantine saw its founding as a direct result of divine will and guidance.
The site of the city, previously called Byzantium, was far away from the threatening barbarians living between the Danube river and Tanais, and well-positioned to monitor the status of the Persian empire in the East. Locally, the city was strategically positioned: the narrow straits of the Hellespont (now called Dardanelles) and Bosporus enveloped Constantinople, making it easy to cut off any naval invasion from the north or the south. It was built on seven hills, making land invasion very difficult. Indeed, Constantinople was never successfully taken by enemy forces until the Fourth Crusade in 1204, and its final demise in the hands of the Ottomans in 1453.
During his reign, Constantine sought to create a strong balance between civil and military powers which had so adversely tainted the stability of the empire up to that time. The Praetorian Guard, responsible for the much of the chaos in the 3rd century, had already been weakened by Diocletian. Under Constantine, they were completely abolished. However, the prefects of the Guard were transformed into civil magistrates. Constantine continued to divide the empire into four large regions, as during the time of the tetrarchy, each administered by a prefect, with the exception of Rome and Constantinople, which had their own prefects. The bureaucracy continued to expand: the regions were further divided into smaller regions, governed by proconsuls, correctors, consulars, and presidents. None of these officials had absolute power; for example the proconsul or governor of a province had the power to execute death sentences, but large fines could only be imposed by the prefect. Thus a provincial magistrate could not easily extort the wealth of rich families for his own gain. The command of the military was transferred to specialized generals, also divided by regions and called counts and dukes. They were not allowed to intervene in civil jurisprudence or administration at all.
Gibbon does criticize some innovations of Constantine. He instituted a divide between troops guarding the frontiers of the empire and palatines (“troops of the court”), who were garrisoned domestically. This resulted in declining discipline in the latter group of troops and internal dissension, as the border troops, despite being exposed to more danger, were paid only two-thirds of the palatines. Afraid of their power, Constantine also dissolved or reduced the size of all the legions and military units. This strategy of dividing up and/or reducing any institution which could become a source of power was characteristic of Constantine.
As we have encountered in the previous post, the increasing number of foreigners in the empire was one of the principle long-term causes of the decline. This was especially true in the reign of Constantine. Barbarians including Germans, Gauls and Scythians continued to make further inroads into the composition of the military, even advancing to important leadership positions. Their services became increasingly necessary as finding volunteers for the Roman legions became more difficult. Gibbon laments that these foreign soldiers did not fully assimilate into Roman society, strongly retaining their national identity and culture within the military.

As they freely mingled with the subjects of the empire, they gradually learned to despise their manners and to imitate their arts. They abjured the implicit reverence which the pride of Rome had exacted from their ignorance, while they acquired the knowledge and possession of those advantages by which alone she supported her declining greatness.
(Chapter XVII)

Gibbon points out that these barbarian soldiers were often entrusted with a war against their own countrymen, and thus were never fully exempt from suspicion. But he does admit that they more frequently held ties of allegiance more important than blood. Gibbon’s concerns about the dilution of Roman culture within the military seems justified at first: how can it be realistic to trust a group of people to fight for the cause of those who just conquered them? Yet throughout the entirety of Volume I there are very few instances of barbarian detachments of the Roman military committing mutiny and turning against their new rulers. Conflicts against barbarians always came from tribes living near the frontier, or actively invading from the outside. Thus, at best, the increasing diversity of the ethnic composition of the Roman army is only a symptom, not a cause, of the decline of the Empire.
Constantine’s other important policies was the imposition of a head or per capita tax. All citizens had to pay a fixed amount of tax, regardless of wealth. While this seems unrealistic at first, according to Gibbon, in practice poor citizens would band together to pay for a single head, while a rich one would pay for the taxes of several. Constantine’s tax rate was also less than that which had been exacted under previous emperors including his father Constantius.
Overall, Gibbon judges the reign of Constantine to be an extended relief from the uncertainty and instability of the previous eras. Thanks to the policies and innovations brought by Constantine, Rome was safe for the time being. The borders of the Empire was secure, culture and the arts flourished, and the strength, legitimacy, and splendour of the imperial government was at its height, encapsulated in the glorious city of Constantinople. However, Gibbon laments the “decline of genius and manly virtue”. Through the relaxing of standards, rise of luxury and pleasures, and perhaps increasing power of the government, the Empire was resembling more and more of the empires of the East which he so strongly detests. To Gibbon, the essence of Rome and its greatness is tied strongly with the ideas of freedom, order, and justice – “unknown to the despotic governments of the east.” As we see throughout his work, Gibbon reserves his highest praise for emperors who possessed the personal qualities which reflected this ideal – a love of learning and literature, self-restraint, personal discipline, athletic vigor, and chastity, among others. While he cannot deny the greatness of Constantine, who did possess some of these qualities, as we will see, the praise for the Christian Constantine is dwarfed by the praise for the pagan emperor Julian, whom Gibbon regards as even worthier for the throne of the Roman Empire.

Constantine’s Sons

Constantine had three sons: Constantine II, Constantius II, and Constans. He also had two brothers: Flavius Dalmatius, who had two sons of his own, Hannibalianus and Dalmatius, and Julius Constantius, whose sons were Gallus and Julian. Initially, his succession plan was that the kingdom would be divided among five of his sons and nephews: Constantine II ruling in Gaul, Constantius in the East, Constans in Italy, West Africa, and Illyricum, Dalmatius in Thrace, Macedonia, Greece, and Hannibalianus in Pontus, Cappadocia, and the Lesser Armenia. (Gallus and Julian were still children at the time of his death.) However, after Constantine’s death in 337, the strength of his influence start rapidly disappearing, and the Empire was once again plunged into a bloodbath. Constantius obtained a forged letter asserting the treachery of Flavius, giving him legitimacy to assassinate the entire Flavian side of the family and many other relatives, leaving only Gallus and Julian. The empire was then reapportioned among only the sons of Constantine: Constantine II to rule over Constantinople, Constantius to rule over Thrace and the East, and Constans ruling over Italy, Africa, and the western Illyricum.
However, this peace was only temporary. Trouble was brewing in the East again. Emboldened by the death of Constantine, the Great King Sapor of the Persian Empire started an invasion. He besieged the stronghold city of Nisibis several times, but was repelled by Constantius. The sons of Constantine were not content with the status quo. In the ensuing power struggle, Constantine II was killed in an ambush by Constans’ troops while trying to invade Italy, and Constans was assassinated by Magnentius, a Roman soldier who was supposedly sick of his ineffectual administration and favor for certain German barbarians. Constantius emerged as the sole remaining survivor, but he had to quickly return from the East to fight Magnentius and Vetranio, a governor of Illyricum who had joined revolt. Constantius’ strong personal qualities were displayed through his clever tactic of luring Vetranio into Sardica and convincing the populace to support him through a rousing speech, giving Vetranio no choice but to surrender. However, it took a large battle at Mursa to subdue Magnentius. Finally, the empire was united once again.
While the bloody conflict that occurred in the aftermath of Constantine’s death showed the instability of an oligarchical monarchy, the Empire was too large to be ruled by a single emperor. Constantius elevated Gallus to the rank of Caesar, sent to rule over the East. However, Gallus was a tyrannical, petty, and luxurious emperor in the mould of Commodus, and was eventually executed by Constantius after being lured to Milan. Constantius, still convinced of the need of a co-emperor, tried again with Julian, brother of Gallus. Initially, being a man of learning and letters, he had resigned himself to be in retirement with no hope of ruling. Despite being the brother of a criminal, he gained the favor of empress Eusebia, who convinces her husband as a suitable and harmless candidate for Caesar. Constantius elevated the unsuspecting Julian to Caesar and immediately sent him to rule over “countries beyond the Alps.”
At this point in time, Rome’s importance was increasingly diminishing. Despite still being a large and historic city, the center of the Empire had clearly shifted to Constantinople. When Constantius visited Rome in 357, it was the first time in 32 years that an emperor had visited the city. It was still a grand occasion, one which resulted in great personal satisfaction for the emperor as he beheld the historic buildings that had been the birthplace of such a powerful empire: the Capitol, the Pantheon, the Forum. However, this was to be the first and only visit for the rest of his life.
Throughout the remainder of his reign, Constantius proved himself as a great military leader in the footsteps of his father. He subdued rebellions of the Quadi and Sarmatian barbarians near the Danube. Unlike the policies of previous emperors, Constantius granted them ample mercy when they surrendered. He then nimbly moved to the East, where Sapor had proposed a humiliating peace treaty which he rejects. In response, Sapor invades the empire again in person, but is stopped after a Pyrrhic victory at the city of Amida. Constantius attempted to retaliate, going forth and besieging Bezabde, but eventually his attempts were unsuccessful.
Despite his military successes, Gibbon viewed Constantius as a fundamentally unfit for being an emperor, judging him as timid and distrustful. He denounces him for allowing eunuchs to gain influence in the court of Constantinople, as Constantius distrusted his own ministers.

The Rise of Julian

Gibbon displays immense admiration to the figure of Julian, devoting many pages to an emperor who ruled for barely over a year (360-1). Gibbon’s fascination centers on Julian’s unlikely origins as a man of letters rather than a soldier. (Perhaps this was something close to Gibbon’s own life.) He portrays the his rise as both unlikely and meteoric, beginning with his surprise at being appointed Caesar at all, as he was set for a scholarly life of pure learning. Having been rudely interrupted from his philosophical studies at Athens, Julian was immediately sent to Gaul, instructed to repel the German barbarians who once again started invading. Despite having a purely academic background with no experience in the military, Gibbon is proud to say that his learning provided the mental virtues necessary for military success:

Yet even this speculative philosophy, which men of business are too apt to despise, had filled the mind of Julian with the noblest precepts and the most shining examples; had animated him with the love of virtue, the desire of fame, and the contempt of death.
(Chapter XIX)

Subverting all expectations, Julian successfully repelled the invasion. At the Battle of Strasbourg, Julian decisively defeated an Alemanni army almost three times his size. He then proceeded to besiege and subdue the Franks, and moved so quickly that the other barbarian tribes were surprised and quickly defeated. Julian’s successes and personal qualities inspired the loyalty of his troops, whereas the same time, Constantius grew wary of his growing power. In response, he demanded some of Julian’s mostly barbarian auxiliaries to march to Rome, in violation of their original recruitment agreement. Despite feeling great sympathy for his men, Julian initially had no intent to rebel, and reluctantly commanded them to follow the order. However, the troops mutinied and forcefully proclaimed Julian as Augustus.
Left with no choice, Julian embraced the title and continued his military expedition, defeating more barbarians and moving towards Italy. He started to encounter resistance, and civil war was once again on the brink, but Constantius fortunately died of sickness and Julian was naturally proclaimed sole emperor in 361.
Julius returned to Constantinople and reigned triumphantly, distinguishing himself through his personal restraint, discipline, and erudition. He liked to judge in court, and often displayed his skills as an orator. He got rid of the excesses of the Imperial palace, dismissing all the servants, eunuchs, and luxuries which contributed to waste. He was chaste, having no known relations with any woman after the death of his wife Helena shortly before he became emperor. He refused to be called a lord or other lofty titles, as he needed no external trappings of power; he was able to distinguish himself as sovereign solely through his personal qualities. Most importantly, Julian worked hard against Christianity and sought to restore paganism. His religious reforms will be discussed later in the context of the overall religious trajectory of the empire. Gibbon’s admiration of Julian does have its limits: he judges him to go too much to the other extreme, violating Aristotle’s maxim of moderation in all things. Julian disdained personal cleanliness and any sort of decent clothing, preferring extreme simplicity and a spartan lifestyle, which drew the ire of some of his more refined subjects. But Gibbon’s overall verdict of his reign is overwhelming adoration:

“Even faction, and religious faction, was constrained to acknowledge the superiority of his genius, in peace as well as in war; and to confess, with a sigh, that the apostate Julian was a lover of his country, and that he deserved the empire of the world.”
(Chapter XXII)

Julian’s untimely demise came when he ventured into the East, worlds apart from the cold and harsh climate of the Western empire. He embarked on an expedition against Persia. From the beginning, there were bad signs: he chose to stay for a period at Antioch, where his extreme restraint and spartan lifestyle were disdained by the opulent and luxurious population. In the initial stages of the invasion, a few important victories were achieved. Through heroic efforts, the entire army crossed the Tigris. Julian then decided to burn all of his ships in order to force his soldiers to keep moving forward. However, their plans were undermined by the guidance of their imposter guide, a Persian noble who pretended to defect to the Romans, but ultimately misled them. Scorched-earth tactics and the hot climate, which the Roman soldiers are unaccustomed to, gradually ate away at the army, and Julian is forced to begin a retreat. However, his reckless behavior on the battlefield, which up to this point had been a a source of inspiration, caught up with him: he was hit by a javelin and he died.

Valentinian and Valens

The sudden death of Julian had disastrous results. Left with no hereditary successor, the military senator Jovian was elected by the troops as a new emperor, and continued the retreat. At that point Sapor, also also exhausted by the war, and seeing his opportunity, proposed an unfair peace treaty which would force the Romans to give up several Eastern cities previously conquered by Galerius and the important fortress of Nisibis. Being desperate to secure his own position as emperor, Jovian accepted the treaty, allowing his army to continue its ragged march back to the Roman Eastern frontier, which they finally reached after having suffered heavy losses. Jovian only reigned for a total of eight months, and his only lasting legacy was the restoration of Christianity. He died after a large feast, ostensibly due to an indigestion.
After Jovian’s death, Valentinian, a prominent military officer who had established himself through campaigns in Africa and Britain, was elected as emperor. He would reign for a total of twelve years. He raised his brother Valens as co-emperor of the East. Both brothers were flawed emperors; Valentinian being a petty, sadistic tyrant who never let go of an insult and fed his enemies to a pair of bears he kept in his palace, and Valens being weak and timid. However, Valentinian also paradoxically accomplished many things during his reign: he developed education and schools, administered the finances well, and kept his impartiality in religious matters. Valentinian also achieved a string of military victories crushing rebellions and invasions in Germany, Britain, and Africa, partially thanks to the outstanding leadership of his general Count Theodosius.
While being weak, Valens’ greatest trait was his readiness to follow his stronger brother’s guidance in all matters. His reign was interrupted early by the rebellion of Procopius, a general who was a loyal devotee of Julian. There were rumors that Julian had really intended Procopius to be his successor before his death. Procopius took advantage of the growing discontent against Valens, and managed to get himself proclaimed emperor in Constantinople while Valens was away in Caesarea. Eventually, the rebellion was quelled thanks to the several important officials and military commanders who were still loyal to Constantine and the legitimate government. Valens’ troubles did not end there, however; a large contingent of Goths, who had previously joined Procopius, marched down led by their leader Athanaric, passing the Danube and invading the provinces of Thrace. Consequently Valens went out with an army to subdue him. In line with his conduct towards his brother, he followed the advice of his generals. The defeat of this invasion took three years, but resulted in a favorable peace treaty which subdued the Goths for several years. Valens’ victories were tainted, however, by the loss of Armenia to Persia, which had previously been ruled by the vassal king Tiranus.
Valentinian’s death finally came after he had just successfully finished defeated the rebellion of the Quadi in the provinces of Rhaetia and Illyria. The vanquished rebels approached his throne asking for mercy, but Valentinian was enraged at their conduct, and in the middle of his rant, a blood vessel broke and he died. At this time, Valentinian’s son Gratian was already 17 years old, and had already been proclaimed Augustus as a boy by his father. But the army, having their own designs, proclaimed the infant other son of Valentinian II as emperor instead. Gibbon praises Gratian’s gracious conduct, who accepted the choice of the army and refrained from starting another civil war.

The Gothic War and the Death of Valens

Valens met his demise a few years later. Gibbon judges the reign of Valens as the start of the fall of the Roman Empire, where “the happiness and security of each individual were personally attacked; and the arts and labours of ages were rudely defaced by the Barbarians of Scythia and Germany” (Chapter XXVI). No longer guided by his brother, Valens fixed his capital in Syria with eyes on the Persian empire to the east. He heard news that the Huns had defeated the Goths in the north. Being under pursuit, the desperate Goths implored the protection of the Roman empire, promising to adhere to its laws and whatever terms the emperor gave them. This was accepted by Valens, as usual, to Gibbon’s immense dissatisfaction. He initially gave them generous terms of capitulation, with the exception of the stipulation that the Gothic children would be held as hostages and dispersed throughout the empire to be educated in the culture of Rome. Valens’ ministers Lupicinus and Maximus, however, corrupted the execution of the treaty, extorting the Goths for purchases of their food and needs, forcing them to even sell their own children. This artificial famine led to discontent, and eventual rebellion: the two Gothic tribes, the Visigoths and Ostrogoths, united under the command of Fritigern and Alavivus and attacked, successfully defeated the Roman army of Lupicinus.
Thus, Gibbon’s repeated unapproval of non-Roman infiltration was shown to be true in this instance. The fundamental catalyst, however, were the provocations and reckless actions of the Roman magistrates. In reaction to the Gothic uprising, another group of Gothic refugees at Hadrianople (modern day Edirne in Turkey) were forcefully ordered to leave Hadrianople without even a few days to gather their belongings. This resulted in a victorious rebellion and these forces joining with that of Fritigern’s. The invading force destroyed large swathes of Roman land and massacred many citizens, exacting their revenge for the mistreatment of them and their children. Intent on crushing the rebellion, Valens sought the assistance of the co-emperor Gratian in the West, who then defeated a horde of Alemani which had risen up in response to his preparations to assist his colleague. Before Gratian could reach Valens, however, the latter’s and Gothic forces met in the Battle of Hadrianople. The Roman cavalry fled and the infantry was compressed into a tight space, resulting in a disastrous defeat for the Romans and the death of Valens. 40,000 Roman soldiers perished, including numerous officers and generals. Empowered by their victory, the Goths then tried to besiege Hadrianople and then Constantinople, but both feeble attempts resulted in failure.
Upon learning of the death of Valens, Gratian, feeling overwhelmed on all sides, sought the assistance of the Imperial council to select an additional emperor to help him continue the fight against the Goths. Theodosius, the son of Count Theodosius who had been a successful general under Valentinian, was selected. While he had built up an impressive military reputation for himself, Theodosius’ election was surprising as his illustrious father had been executed after the death of Valentinian due to suspicions about his growing fame. Under Theodosius, the empire was secured and strengthened, but the defeat at Hadrianople was never revenged. Fritigern died, and the union of the Gothic nation started to collapse. Eventually Athanaric was moved to negotiate a peace treaty with Theodosius. Received honorably by Theodosius in Constantinople, he was extremely impressed by the splendour of the capital. Shortly after, he died, and his funeral was conducted with great respect in the city. Impressed by this display, his remaining troops chose to submit to Theodosius. Further attempts by other Goths forces to invade the empire failed, and four years after the death of Valens, the Gothic war was finally at an end.