Emperor Gratian elevates Flavius Theodosius at Sirmium to Augustus, and gives him authority over all the eastern provinces of the Roman Empire.

Gratian: Western Roman Emperor and Champion of Nicene Christianity (367-383 CE)

Flavius Gratianus, commonly known as Gratian, served as the Roman Emperor of the Western Roman Empire from 367 CE until his death on 25 August 383 CE. Born on 18 April 359 CE, he was the eldest son of Emperor Valentinian I, a powerful ruler who solidified Roman frontiers. Gratian was groomed for imperial responsibilities from a young age, accompanying his father on various military campaigns along the vital Rhine and Danube frontiers. His rise to the rank of *Augustus* in 367 CE signified his official designation as co-emperor, sharing the weighty imperial authority with his father.

Accession and Initial Rule

Upon the sudden death of Valentinian I in 375 CE, Gratian formally assumed full governance of the Western provinces. In a somewhat unusual arrangement, his half-brother, Valentinian II, was also acclaimed emperor in Pannonia by the army, leading to a co-emperorship in the West. Gratian, based primarily in Gaul and later Milan, primarily oversaw the vast territories of the Western Roman Empire, while his paternal uncle, Valens, continued to reign as Emperor of the Eastern Roman Empire from Constantinople.

Military Campaigns and the Aftermath of Adrianople

Gratian proved to be a capable military leader in his early reign. He successfully led a significant campaign across the Rhine frontier, engaging the Lentienses, a sub-tribe of the Alamanni. His decisive victory at the Battle of Argentovaria in 378 CE forced the tribe to surrender and brought a temporary stability to the Germanic frontier. However, this success was overshadowed by a catastrophic event in the East that same year: the Battle of Adrianople. During this pivotal engagement, Emperor Valens, Gratian's uncle, was tragically killed fighting the Visigoths, leading to one of the most devastating defeats in Roman history and leaving the Eastern Empire in disarray. Faced with this monumental crisis and recognizing the urgent need for strong leadership, Gratian made the critical decision in 379 CE to elevate Theodosius, a skilled general, to the position of Eastern Roman Emperor, entrusting him with the monumental task of stabilizing the ravaged East.

Religious Policies and the Decline of Paganism

Gratian is particularly notable for his profound devotion to Nicene Christianity and his aggressive stance against traditional Roman polytheism, significantly accelerating the Christianization of the Roman state. His key religious policies included:

These actions marked a decisive shift in imperial religious policy, signaling the end of state-sponsored paganism and the burgeoning dominance of Christianity.

Later Reign and Demise

Gratian's reign also saw a significant administrative change when the city of Cularo, located on the Isère river in Roman Gaul, was renamed *Gratianopolis* in his honor. This city later evolved into the modern French city of Grenoble. However, his later years were marred by challenges, particularly a growing unpopularity among his troops and segments of the populace, partly due to his perceived favoritism towards Alan mercenaries and his increasing piety, which was seen as neglect of military affairs. In 383 CE, these tensions culminated in a major rebellion led by the ambitious usurper Magnus Maximus, who had been proclaimed emperor by his troops in Britain. As Gratian marched his army towards Lutetia (modern-day Paris) to confront the usurper, a significant portion of his forces deserted him. Forced to flee, Gratian sought refuge in Lyon but was subsequently pursued and murdered on 25 August 383 CE, reportedly at the hands of Andragathius, Magnus Maximus's *magister equitum* (Master of Horse).

Theodosius I: Theodosius the Great and the Final Unification of the Roman Empire (379-395 CE)

Born on 11 January 347 CE in Hispania (modern-day Spain), Theodosius I, also revered as Theodosius the Great, reigned as Roman Emperor from 379 CE until his death on 17 January 395 CE. His sixteen-year tenure was marked by critical military successes, including a crucial resolution to the conflict with the Goths and victories in two significant civil wars. He is historically recognized for playing an instrumental role in firmly establishing the Nicene Creed as the definitive doctrine for Christianity throughout the Empire. Crucially, Theodosius holds the unique distinction of being the last Roman emperor to govern the entire Roman Empire before its administration was permanently divided into distinct Western and Eastern courts after his death.

Early Life and Military Career

Theodosius was the son of a high-ranking general, Theodosius the Elder, under whose tutelage he rapidly advanced through the ranks of the Roman Army. By 374 CE, he held an independent command in the province of Moesia, where he achieved notable successes against invading Sarmatian tribes. However, his promising career was abruptly interrupted when he was forced into retirement, and his father was executed under circumstances that remain somewhat obscure. Theodosius's return to prominence was swift, aided by a series of political maneuvers and internal purges at the court of Emperor Gratian. In 379 CE, following the devastating defeat at Adrianople and the death of Emperor Valens, Gratian, facing an existential threat to the Eastern Empire, appointed Theodosius as his co-emperor, specifically entrusting him with the monumental task of stabilizing the military situation in the East.

Addressing the Gothic Crisis and Foreign Policy

Upon his accession, Theodosius inherited an Eastern Empire with severely depleted armies and resources, insufficient to decisively expel the Gothic invaders. Recognizing the pragmatic necessity of a new approach, he embarked on a diplomatic strategy. In 382 CE, he negotiated a groundbreaking treaty with the Goths, allowing them to settle *en masse* south of the Danube as *foederati* – autonomous allies within the Empire's borders. While this agreement brought immediate peace and provided a much-needed influx of manpower for the Roman army, their unique status as an independent entity within Roman territory would pose significant challenges for subsequent emperors. Beyond the Goths, Theodosius also secured a crucial diplomatic achievement in 386 CE by signing a treaty with the formidable Sasanian Empire of Persia. This agreement effectively partitioned the long-disputed Kingdom of Armenia, establishing a durable, albeit temporary, peace between the two dominant powers of the ancient world.

Religious Policies and the Ascendancy of Orthodoxy

Theodosius was a staunch advocate of the Nicene Christian doctrine of consubstantiality (the belief in the co-equal and co-eternal nature of God the Father and God the Son) and a resolute opponent of Arianism, which held that Jesus was created by God and thus subordinate. In 381 CE, he convened the First Council of Constantinople, a pivotal ecclesiastical gathering that officially reaffirmed the Nicene Creed as Christian orthodoxy and formally condemned Arianism as a heresy. While Theodosius initially showed some leniency towards traditional pagan cults, even appointing non-Christians to high offices during his earlier reign, his later policies became increasingly assertive. He is criticized by some historians for failing to prevent or adequately punish the destruction of several significant Hellenistic temples of classical antiquity, such as the renowned Serapeum of Alexandria in 391 CE, by fervent Christian zealots. The Serapeum, a massive temple complex and repository of knowledge, symbolized the decline of paganism under Christian dominance.

Consolidation of Power and Legacy

During his earlier reign, Theodosius focused on the Eastern provinces, while the West was overseen by Emperors Gratian and Valentinian II, whose sister Galla he married, strengthening his dynastic ties. Theodosius also dedicated considerable resources to improving his imperial capital and primary residence, Constantinople. Most notably, he undertook a significant expansion of the Forum Tauri, transforming it into the largest public square known in antiquity, a testament to the city's growing prominence. Theodosius twice marched west to assert his authority: first in 388 CE, after Gratian's assassination, to defeat the usurper Magnus Maximus at the Battle of the Save; and again in 394 CE, following the death of Valentinian II, to decisively defeat the second pretender, Eugenius, at the Battle of the Frigidus. His final victory in September 394 CE momentarily made him the sole master of the entire Roman Empire, a feat not achieved by any emperor after him. He died just a few months later, and the Empire was formally divided between his two sons: Arcadius inherited the Eastern half, and Honorius the Western half.

Historically, Theodosius has been described as a diligent administrator, austere in his personal habits, merciful, and a deeply devout Christian. For centuries after his death, he was largely revered as the ultimate champion of Christian orthodoxy, who decisively eradicated paganism. However, modern scholarship often re-evaluates this narrative, suggesting it is partly an interpretation by Christian writers rather than a complete and accurate representation of historical reality, highlighting the complexities and gradual nature of the shift from paganism to Christianity. He is fairly credited with presiding over a notable revival in classical art, which some historians have termed a "Theodosian Renaissance." While his pacification of the Goths brought vital peace during his lifetime, their unique autonomous status within Roman borders ultimately created significant problems for succeeding emperors. Theodosius has also faced criticism for prioritizing his own dynastic interests, a pursuit that contributed to two costly civil wars. His sons, Arcadius and Honorius, proved to be weak and often incapable rulers, presiding over a period marked by escalating foreign invasions and disruptive court intrigues that severely weakened both halves of the Empire. Nevertheless, the descendants of Theodosius governed the Roman world for the next six decades, and the enduring East-West division he formalized persisted until the ultimate fall of the Western Roman Empire in the late 5th century CE.

Frequently Asked Questions About Gratian and Theodosius I

Who was Gratian and what was his significance?
Gratian was Emperor of the Western Roman Empire from 367 to 383 CE. He is significant for being the first emperor to refuse the pagan title of *Pontifex Maximus*, for ordering the removal of the Altar of Victory from the Roman Senate, and for co-issuing the Edict of Thessalonica, which declared Nicene Christianity the official state religion of the Roman Empire. His reign marked a crucial turning point in the Christianization of the Roman state.
What was the Edict of Thessalonica?
The Edict of Thessalonica, issued in 380 CE by Emperors Theodosius I, Gratian, and Valentinian II, declared Nicene (Trinitarian) Christianity as the sole legitimate religion of the Roman Empire. It mandated adherence to the Nicene Creed and condemned other Christian beliefs, such as Arianism, as heresy, making them unlawful.
How did Gratian's reign end?
Gratian's reign ended in 383 CE when he faced a rebellion by the usurper Magnus Maximus. As his army deserted him near Lutetia (Paris), he fled to Lyon and was subsequently murdered by agents of Magnus Maximus, marking the triumph of the usurpation.
Who was Theodosius I, and why is he called "the Great"?
Theodosius I, also known as Theodosius the Great, was Roman Emperor from 379 to 395 CE. He earned the epithet "the Great" for his military achievements, including resolving the Gothic War, and for his instrumental role in establishing Nicene Christianity as the official state doctrine. He was also the last emperor to rule the entire Roman Empire before its permanent administrative division into East and West.
What was Theodosius I's relationship with the Goths?
Theodosius I inherited a devastating war with the Goths after the Battle of Adrianople. Rather than outright expelling them, he signed a treaty in 382 CE, allowing them to settle within the Empire as *foederati* (autonomous allies). While this provided immediate peace and manpower, their status as an independent entity within Roman borders created long-term challenges for the Empire.
What significant religious actions did Theodosius I take?
Theodosius I was a devout Nicene Christian. He co-issued the Edict of Thessalonica (380 CE) and convened the First Council of Constantinople (381 CE), which solidified the Nicene Creed as orthodoxy and condemned Arianism. Although he didn't immediately suppress all pagan cults, his reign saw the accelerated decline of paganism, notably with instances of temple destruction like the Serapeum of Alexandria by Christian zealots.
How did Theodosius I become sole emperor, and what happened after his death?
Theodosius I became sole emperor after defeating two usurpers, Magnus Maximus (in 388 CE) and Eugenius (in 394 CE), who had seized control of the Western Roman Empire. His victory at the Battle of the Frigidus in 394 CE made him master of the entire Roman world. Upon his death in 395 CE, the Empire was formally and permanently divided between his two sons, Arcadius (East) and Honorius (West), a division that persisted until the fall of the Western Empire.