[1][2][3] The plague is named for the Byzantine Emperor Justinian I (r. 527–565) who, according to his court historian Procopius, contracted the disease and recovered in 542, at the height of the epidemic which killed about a fifth of the population in the imperial capital.

[4][1] As the first episode of the first plague pandemic, it had profound economic, social, and political effects across Europe and the Near East and cultural and religious impact on Eastern Roman society.

[citation needed] Procopius, in a passage closely modelled on Thucydides, recorded that at its peak the plague was killing 10,000 people in Constantinople daily,[14] but the accuracy of the figure is in question, and the true number will probably never be known.

[15] Given such circumstances, it is highly probable that a sudden increase in mortality rates may not have been as accurately recorded, hence why the overall death toll is based on an estimate.

As the empire tried to fund the projects, the plague caused tax revenues to decline through the massive number of deaths and the disruption of agriculture and trade.

Justinian swiftly enacted new legislation to deal more efficiently with the glut of inheritance suits being brought as a result of victims dying intestate.

[32][33] This conclusion is based on historical descriptions of the clinical manifestations of the disease[34] and the detection of Y. pestis DNA from human remains at ancient grave sites dated to that period.

[35][36] Genetic studies of modern and ancient Yersinia pestis DNA suggest that the origin of the Justinian plague was in Central Asia.

[8] This finding suggests that the expansion of nomadic peoples who moved across the Eurasian steppe, such as the Xiongnu and the later Huns, had a role in spreading plague to West Eurasia from an origin in Central Asia.

[30] According to one view, the initial plague ultimately killed perhaps 40% of the city's inhabitants and caused the deaths of up to a quarter of the human population of the Eastern Mediterranean.

[citation needed] A revisionist view expressed by scholars, such as Lee Mordechai and Merle Eisenberg, argues that the mortality of the Justinian Plague was far lower than previously believed.

Sarris also provides up-to-date discussion of the genetic evidence, including the suggestion that the plague may have entered Western Eurasia via more than one route, and perhaps struck England before Constantinople.