Growing scientific evidence from modern climate science is loaded with implications for the environmental history of the Roman Empire and its successor societies. The written and archaeological evidence, although richer than commonly realized, is unevenly distributed over time and space. A first synthesis of what the written records and multiple natural archives (multi-proxy data) indicate about climate change and variability across western Eurasia from c. 100 b.c. to 800 a.d. confirms that the Roman Empire rose during a period of stable and favorable climatic conditions, which deteriorated during the Empire's third-century crisis. A second, briefer period of favorable conditions coincided with the Empire's recovery in the fourth century; regional differences in climate conditions parallel the diverging fates of the eastern and western Empires in subsequent centuries. Climate conditions beyond the Empire's boundaries also played an important role by affecting food production in the Nile valley, and by encouraging two major migrations and invasions of pastoral peoples from Central Asia.

Many infectious diseases are thought to have emerged in humans after the Neolithic revolution. Although it is broadly accepted that this also applies to measles, the exact date of emergence for this disease is controversial. We sequenced the genome of a 1912 measles virus and used selection-aware molecular clock modeling to determine the divergence date of measles virus and rinderpest virus. This divergence date represents the earliest possible date for the establishment of measles in human populations. Our analyses show that the measles virus potentially arose as early as the sixth century BCE, possibly coinciding with the rise of large cities.

Pandemic events are surpassingly rare in human history. Yet the period we call late antiquity could be considered the age of pandemic disease. It began and ended with the Antonine plague that erupted in the mid-160s A.D. and the Justinianic plague of the mid-6th c. Modern interest in these pandemics has waxed and waned. It was long taken for granted that these events played a major rôle in the fate of the Roman empire. In the mid-20th c., however, attention subsided. Historical demography struggled to make inroads into the discipline of ancient history. In the case of the Antonine plague, a critical article of J. F. Gilliam turned focus away from the disease for a generation. Only in the last 20 years, with the rise of historical demography in ancient studies, and a broader interest in environmental history, have the Antonine and Justinianic plagues received their proper due. Attention has focused on the epidemiology and impact of these events. The Antonine plague is most plausibly identified as smallpox, based on the presentation of the disease described by the contemporary physician Galen, and should qualify as the first pandemic in all of human history. It struck the empire at the apex of its power and prosperity. Its severe demographic effects now seem widely accepted, although there is lively debate about its long-term geopolitical and social consequences. For the Justinianic plague neither its demographic scope nor the long-range consequences are in doubt. Securely identified by both clinical description and paleomolecular evidence, Yersinia pestis arrived in 541 and struck recurrently for over two centuries; like the Black Death in the 14th c., the first bubonic plague fundamentally reshaped the trajectory of European populations.

No abstract

The papyri of Roman Egypt provide some of the most important quantifiable data from a first-millennium economy. This paper builds a new dataset of wheat prices, land prices, rents, and wages over the entire period of Roman control in Egypt. Movements in both nominal and real prices over these centuries suggest periods of intensive and extensive economic growth as well as contraction. Across a timeframe that covers several severe mortality shocks, demographic changes appear to be an important, but by no means the only, force behind changes in factor prices.