A Catalytic Force: A Guest Post by Colin Elliot

Historian Colin Elliot takes on the invisible enemy that contributed to the fall of an empire at the height of its power. Elliot examines the The Antonine Plague, one of the most devastating pandemics of ancient times, from a socioeconomic perspective. Peering into the political climate and class structure, this is an insightful look at the downfall of the Roman Empire. Read on for an exclusive essay from Colin on writing Pox Romana.

Since my undergraduate years, I’ve been captivated by the fall of the Pax Romana, the Roman Empire’s two-century era of peace and prosperity. No single war or economic disaster fully explains its collapse. While the tyrannical rule of Commodus, Marcus Aurelius’ son, played a role, it wasn’t the whole story. Among the mysteries of this period, the Antonine Plague really stands out. It was a disease described by ancient authors as devastating—killing millions—yet it seems almost invisible, at least superficially, in the archaeological record. Was this mysterious disease a catastrophic pandemic—the Roman Empire’s Black Death—or a minor event exaggerated by ancient authors? As I began looking into the mystery, I noticed some strange overlaps between climate events, especially droughts in key agricultural regions like Egypt, and accounts of disease outbreaks. There was clearly something big happening at the time of the Pax Romana’s fall. 

I scoured every possible source from 150 to 200 AD—literary accounts, inscriptions, coin legends—anything hinting at disease or crisis. I also benefitted from generous collaborators who shared their research with me—from prices in Egyptian papyrus documents to pottery shards in Roman London. One unique aspect of Pox Romana is that it takes readers through the history-writing process—how does a historian sift through so much circumstantial and fragmentary evidence to put together a coherent story of the collapse of a complex society? A lot happened during the decade or so that the Antonine plague weaved back and forth across the Empire—two border wars broke out, the army faced mass desertions, slaves revolted, the coinage was debased, mines and quarries inexplicably stopped producing—but how much of these things were caused by plague, and how much of it was due to intrinsic failures in the Roman Empire’s economic and political systems?

But some of the biggest surprises in the book come from the unique environment in which it was written: during the Covid-19 pandemic. That pandemic showed us that while major disease outbreaks are devastating enough on their own, they also carry profound social and cultural weight. In the case of the Antomine plague, I really started noticing a pronounced sense of fear and anxiety in the sources. The Antonine Plague likely killed only a small fraction of the population, but its wider impact was clearly immense. For Romans, for example, disease and religion were inseparable. Plagues were not a result of biological forces, but spiritual ones. And I began seeing connections between plague outbreaks and religious scapegoating or even persecutions. We have sources noting how Christians especially stuck out for non-compliance with mitigation measures, like inscribing verses to Apollo on houses or erecting cult statues. So in the end, the pandemic wasn’t just a disease outbreak that came and went; it was a catalytic force that exposed pre-existing frailties in the Roman imperial system, accelerated the forces of economic and social decline and even helped reshape how Romans viewed their world.