Antonine Plague

The Antonine Plague, likely caused by smallpox or a similar virus, struck the Roman Empire around 165-180 AD during Emperor Marcus Aurelius’s reign. It spread through trade routes and military movements, causing high fever, rash, and severe illness. The disease led to a significant decline in the population—potentially killing around 5 million people—and weakened Rome's economy and military. The outbreak challenged the empire’s resilience, highlighting how infectious diseases can impact large societies and geopolitical stability.