How America Got So Sick

"Galen had been summoned, however, to help fight a different kind of invader. A plague, likely an early variant of smallpox, had traveled to Aquileia with the troops, and held the city in its grip. The emperors fled, but Verus succumbed to the disease on the road to Rome. Galen tried to slow the wave of illness, but most of the people in Aquileia perished."

"They represented just a sliver of the eventual victims of the Antonine Plague, also known as Galen's Plague, which killed at least 1 million people throughout the Roman empire. It was possibly the world's first true pandemic, and haunted the empire for the rest of the Pax Romana, which ended in 180 with Aurelius's death. The details of the pandemic-the exact pathogen, the true number of victims-are subjects of debate, and might never be fully settled."

Galen arrived in Aquileia in winter 168 C.E. after the city’s fortifications had deteriorated. The Roman co-emperors raised legions and rebuilt defenses to confront Germanic invaders across the Danube. A plague, likely an early smallpox variant, traveled with troops and devastated Aquileia; Emperor Lucius Verus died while fleeing. Galen attempted to contain the outbreak but most residents perished. The Antonine Plague killed at least one million across the Roman Empire and possibly constituted the first true pandemic. The pandemic compounded existing stresses—food shortages, migrations, overcrowding—spreading panic, mistrust, and weakening civic and religious authority, hastening imperial decline.

Read at The Atlantic