The Antonine Plague: A Devastation That Reshaped the Roman Empire

The Antonine Plague, also known as the Plague of Galen (named after the doctor who described it), broke out in 165 CE during the peak of Rome's power under the rule of Marcus Aurelius Antoninus, the last of the Five Good Emperors.

This devastating event stretched across the entire Roman Empire until 180 CE and was followed by a second wave from 251-266 CE, deepening the crisis initiated by the first outbreak. Some historians view the plague as a pivotal moment marking the start of the Western Roman Empire's decline and contributing to its eventual collapse.

Symptoms

Galen, a prominent Greek physician living from 129 to around 216 CE and the author of "Methodus Medendi," observed this epidemic firsthand and documented its symptoms and progression. He detailed common symptoms including fever, diarrhea, vomiting, excessive thirst, swollen throat, and coughing. Notably, Galen observed that the diarrhea had a blackish color, indicating possible gastrointestinal bleeding.

Furthermore, he described the presence of a pervasive foul odor from the breath of the afflicted and a distinctive rash covering the body, characterized by red and black spots.

People afflicted by the disease typically experienced symptoms for around two weeks. Not everyone infected succumbed to the illness; survivors gained immunity against future outbreaks. Drawing from Galen's accounts, contemporary scholars believe the epidemic that swept through the empire was likely smallpox.

Origins

Given the accounts of a similar epidemic in the Han Dynasty China around 151 to 185 CE, many historians suggest that the plague may have started in the Far East, traveling westward via the Silk Road and maritime trade routes. The Roman Empire's initial encounter with the disease is thought to have occurred during its siege of Seleucia, located on the empire's eastern frontier. Soldiers returning from this campaign are believed to have carried the disease back home, spreading it further to troops along the Rhine River. This pathway is considered the most plausible source of the outbreak.

However, alternative tales emerged to account for the epidemic's origins. One such myth recounts that Roman General Lucius Verus unleashed the disease by opening a sealed tomb in Seleucia, violating a sacred promise not to loot the city, thus incurring divine punishment. Another version claims the plague was released from a golden casket within the Temple of Apollo in Babylon after being disturbed by a Roman soldier. Additionally, there were narratives blaming the emergence of Christianity for inciting divine wrath. These stories reflect the varied attempts to understand and explain the devastating impact of the plague on the Roman Empire.

Death rate

Scholars continue to vigorously debate the impact and aftermath of the epidemic on the Roman Empire, particularly concerning the methodology for calculating the death toll. According to the Roman historian Dio Cassius, Rome experienced as many as 2,000 deaths daily at the peak of the initial outbreak. This number significantly increased during the second wave, with death rates purportedly reaching 5,000 per day.

The particularly high mortality rate is attributed to the population's lack of immunity to this new disease, a common occurrence when an infectious disease first impacts a 'naive population'—one without prior exposure or immunity. Estimates suggest that the epidemic claimed the lives of a quarter to a third of the population, totalling 60-70 million people across the empire. It's widely accepted that Lucius Verus, co-emperor with Marcus Aurelius, succumbed to the disease in 169 CE, followed by Marcus Aurelius 11 years later. Notably, it was Verus's troops, returning from the Near East, who played a pivotal role in spreading the disease throughout the empire.

Military Impact

The Antonine Plague severely affected Rome's military, decimating the ranks of 28 legions, which totalled approximately 150,000 men. The legionaries, despite their training and preparation, were not immune to the disease, leading to manpower shortages, especially along the German frontiers. This weakened Rome's defensive capabilities, prompting Emperor Marcus Aurelius to recruit from various societal segments, including freed slaves and gladiators, to fill the gaps. This makeshift army struggled to defend the empire, notably failing to prevent Germanic tribes from crossing the Rhine River for the first time in over two centuries .

Economic and Societal Disruptions

The plague's impact extended beyond the military, causing widespread economic disruption and societal upheaval. A significant reduction in the population meant fewer taxpayers, recruits for the army, and laborers for farms and businesses. The resulting scarcity of crops and goods led to steep price increases, further straining an already stressed economy. Moreover, the decrease in available labor forced an increase in wages for those who survived, complicating the financial stability of remaining businesses and the state itself.

Effect on Religion

Interestingly, the Antonine Plague also had profound effects on religious practices and beliefs within the empire. Emperor Marcus Aurelius's decision to persecute Christians, blaming them for angering the gods and thereby causing the plague, ironically led to the growth of Christianity. Christians' willingness to care for the sick and provide basic needs fostered good relations with their pagan neighbors, contrasting with the flight of many pagans from affected areas. This period of crisis thus contributed to the expansion of Christianity, laying the groundwork for its eventual dominance in the empire.

The Antonine Plague not only brought immediate suffering and death but also long-term consequences that contributed to the weakening of the Roman Empire. It showcased the vulnerabilities of a highly interconnected and urbanized society to pandemic diseases. Despite this, the Roman response to the crisis also highlighted the resilience and adaptability of its society and governance, offering lessons on handling pandemics that resonate even in modern times.